There are places in the world where you can get to know long-vanished nations and their former glory: Egypt, China, Greece... Bulgaria also makes it on this list. Long before this country appeared on Europe's map, an ancient nation inhabited its lands, and left behind rich remains – tombs and burial mounds, rock shrines and forts, fortifications and mysterious rock niches.

These people were the ancient Thracians.

Together with the Slavs and the so-called Proto-Bulgarians, the Thracians are considered to be the forefathers of modern Bulgarians, whose nation emerged in the early Middle Ages. While the Slavs and the Proto-Bulgarians were recent arrivals in the Balkans, the Thracians had lived here for many centuries, and were not just some insignificant tribe. According to Herodotus, the Thracians were the second most numerous people of the ancient world after the Indians (he was wrong on that matter). They actively took part in the international politics of the day and were divided into several tribes, some of which created their own kingdoms and even minted their own coins – a sign of economic strength and political importance. They were eventually conquered by the Romans and many of them then adopted Roman or Greek lifestyles and habits. However, they largely preserved their culture until the arrival of Christianity. Eventually they became part of young Bulgaria.

Perperikon rock city

Sadly, the Thracians were reluctant chroniclers and left almost no written sources. What we do know, or believe we know, about their history, beliefs and culture is derived from archaeological research and ancient Greek and Roman sources.

The Thracians may have disappeared, but much has remained of their treasures: their coins, tombs and shrines, pottery, weapons and heroes – both mythical ones such as Orpheus and historical figures like Spartacus.

Bulgaria is dotted with Thracian sites, and visiting the most interesting of these is a true delight.

One of the most famous sites created by the Thracians is the rock city of Perperikon. Situated on a peak overlooking a river valley in the Rhodope, Perperikon was a rock settlement and a major Thracian shrine which flourished in Antiquity and attracted devotees from far and wide. There is no hard evidence, but some historians suggest that Perperikon was indeed the famed oracle of Dionysus, which predicted the glorious future of both Alexander of Macedon and of Augustus. Faith was the raison d'être for the rock city's existence but life there did not come to an end when the ancient gods gave way to Christianity. Perperikon became a major episcopal centre adorned with a basilica on the site of the erstwhile pagan shrine. It was abandoned during the Ottoman period.

Begliktash megalithic shrine

In recent years Perperikon was hailed by the Bulgarian media as a rival to Machu Picchu. This comparison may be a bit farfetched, but it definitely is a must-see.

Perperikon is not the only site the Thracians carved from rock. Between the 2nd millennium and the middle of the 1st millennium BC, they were very much into creating megaliths. They built shrines on rocky peaks, carved niches and tombs at precipitous heights, and built dolmens and stone circles.

These all represented the Thracian belief in the two powerful, yet nameless deities who had created and ruled over the universe: the Great Goddess and her son and lover, the Great God. She represented the dark powers of the underworld and was symbolised by rock caves and crevices, while he made himself visible in light, fire and prominent rock formations.

Belintash megalithic shrine

Belintash is one of the best known Thracians rock shrines. Located in the Rhodope, the high plateau that rises over a mountain valley is surrounded by a protective wall of neighbouring peaks. Stone carvings, channels and basins are cut into the rock surface. When the sanctuary was active, they may have been filled with wine and the blood of sacrificial animals – or maybe were used for making sacred wine. The inner sanctum of the shrine, the "holy of holies," was at the narrow tip of the plateau, which rises above the rest of the area, proclaiming its importance.

The rock sanctuary at Tatul, also in the Rhodope, is now advertised as the burial place of none lesser than Orpheus. Yes, we know that the famous musician, who was able to enchant animals and melt the stone-cold heart of the lord of the Underworld, was a mythological figure. But some Bulgarian historians believe that mythical Orpheus was based on an actual Thracian man, who did something of immense importance – he reformed the Thracian religion by introducing into it the figure of the enlightened god, Apollo. Supposedly, this real-life Orpheus was buried in a spectacular tomb carved into a prominent rock at Tatul.

Bivolyane megalithic shrine

Located deep in the Strandzha forest, Begliktash is another popular Thracian megalithic shrine. In Antiquity the massive boulders that now stand in a clearing in the dense oak forest were a centre of religious activity. Some boulders have even been connected to particular ancient Thracian rituals (as we lack any detailed information about the Thracian religion, what follows is conjecture). At Begliktash, you will see rocks identified as a "sun dial", a labyrinth, and a sacred bed where the Thracian priest and/or king was supposed to perform a ritual sexual act with the shrine's priestess. One huge structure is believed to be the largest dolmen in Bulgaria and a royal tomb, while a great heart-shaped boulder is said to touch the ground at only two points.

There are lesser known Thracian rock shrines that also deserve attention, such as that on a rocky plateau near the Rhodope village of Bivolyane. The most peculiar feature of Harman Kaya sanctuary are two round pads covered with what appear to be channels and circles. No one knows what exactly they were, but the hypothesis that they were used to measure time is quite popular.

Asara megalithic shrine

Asara, near the village of Angel Voyvoda in the Haskovo region, is believed to be not just an ancient rock shrine and a fort, but also an astronomical observatory. Perched on a 600-metre high hill, the site includes several oddly shaped rocks, and on top of the highest there are two graves. For history buffs, of whom there are many in Bulgaria, these graves and the rock-hewn steps leading to them are the first stone calendar in the world, whatever that might mean. For more conservative archaeologists, they are the steps to an altar.

The ancient Thracians also created hundreds of dolmens. Today, these structures are mostly to be found in the Strandzha and Sakar mountains. Most are small and often in places far removed from the tourist trail. One, however, stands out. The dolmen near the village of Hlyabovo, near Haskovo, is a huge affair. This family burial ground has three adjoining chambers where artefacts were found that indicate it was in use for five centuries.

The dolmen at Hlyabovo is among the largest and best preserved

Two stone circles built by the Thracians still survive, sort of. The most spectacular of the two is near Dolni Glavanak village, in the Rhodope. Situated on a low ridge overgrown with thick oak forest, the stone circle consists of 15 rocks about 1.5m high, with a diameter of about 10m. The other was discovered under a tumulus near the Staro Zhelezare village, in the Plovdiv region. Sadly, after archaeologists left the site the elements took their toll and now the mysterious structure, which is millennia old, has almost disappeared.

Rock niches are an enigmatic practice indulged in by the Thracians in the Eastern Rhodope. Less than a metre high, the niches are usually trapezoid, but are present in a variety of other shapes: circular, rectangular, square. Most of them are hewn at precipitous heights.

A Thracian burial mound, in the Valley of Thracian Kings, ravaged by treasure hunters

More than 200 groups of niches have been discovered so far, with the greatest concentration at Gluhite Kamani, Madzharovo and Valche Pole. Of course a dearth of information only opens the door of the imagination. Some scientists believe that the rock niches were made to house the burial urns of cremated Thracians who could not afford the more expensive and prestigious rock tombs. However, the bottoms of some of the niches are angled upwards, making it impossible to put anything inside them. Others claim that the niches were hewn by adolescent Thracian boys as part of an initiation ceremony. According to a third hypothesis, the niches depict the stars and the constellations in the heavens, while a fourth proposes that they were a sort of map, indicating the whereabouts of ancient gold mines. According to yet another idea, the niches are scaled-down models of dolmens and rock tombs or, more interestingly, of the cave that symbolises the womb of the Great Goddess.

By the middle of the 1st millennium BC, the Thracians had stopped creating megaliths. No one knows why. What is certain is that they started building monumental tombs for their elite instead. These were hidden under massive mounds of earth, which still dot almost every corner of the Bulgarian lands.

Rock niches by Dolno Cherkovishte

The largest concentration of Thracian burial mounds is in the so-called Valley of Thracian Kings, located between the Stara Planina and the Sredna Gora mountain ranges. Here, you can find arguably the most emblematic tomb the Thracians ever created.

The Thracian tomb at Kazanlak has captured the public imagination since its chance discovery in 1944. Many historians have surveyed it, and UNESCO added it to its list of world heritage sites, in 1979. Plundered in Antiquity, the tomb nevertheless preserves skilfully painted murals of a couple surrounded by their servants. The gentleness with which the man holds the lady's white hand is still touching, 2,400 years after the paint was applied, but what the scene represents remains a mystery. Is it a farewell feast for him, the dead, and her, the living? Is it a depiction of the Thracian custom of killing the widow and burying her with her husband? Is it how the Thracians imagined the eternal bliss of the afterlife? Perhaps it is all about the sacred marriage between the deified deceased and the Great Goddess of the underworld. The style and skill of the painting indicate that the artist may have been a Greek hired by the owner of the tomb, evidence of the active contacts between the Greeks and the Thracians at the time.

The Kazanlak Tomb is UNESCO listed because of its fine murals

The tomb hidden in the Golyama Kosmatka mound was not plundered, and its architecture is truly impressive. The structure has a 13-metre long corridor and two antechambers, the second of which is round, with a cupola, and is protected by a marble door. The rectangular burial chamber was hewn into a 60-tonne monolith and contained more than 70 items: a wealth of expensive weapons and precious objects, including a beautiful gold wreath.

The most astonishing find from Golyama Kosmatka, however, was discovered buried in the mound, not in the tomb itself. It was a beautiful bronze head of a man with an unruly beard and strong features. The head was probably an effigy of the deceased that was cut off from an actual, life-size statue.

For the Thracians, big game hunting was sacred. An activity reserved for aristocrats, it was a symbol of royal power. Every year whoever was king would go on a sacred boar hunt to demonstrate that he was still strong enough to bear the crown. In the afterlife, the Thracians believed, there would also be hunting, and so the hunt became a major theme in Thracian art. The Aleksandrovo Tomb is one of the finest examples, with its chamber paintings of men – on foot and on horseback – chasing deer and boar. The antechamber is also decorated with mysterious depictions of battles, or what might be dances between riders and naked young men.

The stone circle at Staro Zhelezhare is now almost lost to the elements due to neglect

The vivid figures of the Aleksandrovo Tomb murals are probably the work of a Thracian artist, and the painstakingly depicted details of weapons, harnesses and clothing are an important source not only of the beliefs of the ancient Thracians, but also of their everyday life.

Most of the impressive Thracian tombs and sites are located in southern Bulgaria, but there are some exceptions. North of the Stara Planina, the Sboryanovo nature and history reserve near Isperih is one of the best places for Thracian tourism in Bulgaria. Here are the remains of Helis, a Thracian stronghold and trading centre from the 4th-3th centuries, and several shrines and tumuli.

One of the burial mounds preserves an astounding monument of Thracian art, the first and so far the only example of Thracian sculpture. The stone burial beds of a deceased Thracian aristocrat and his wife lie in the chamber, watched over by a row of 10 caryatids with wide-open eyes and long arms. These rather crude figures were probably Thracian rather than Greek made. The mural above them, however, is a lot more intricate. The deceased, on horseback, is receiving the wreath of immortality from a tall, regal woman, the Great Goddess of the Thracians. Excavated in 1982, the tomb is now on the UNESCO World Heritage List.

The outstanding decoration of Sveshtari Tomb is why this Thracian monument was declared an UNESCO site

Thracian treasures are another hallmark of this ancient culture. The Thracian kings and noblemen drank wine from cups of gold and silver, and priests used elaborately decorated vessels in religious rituals. Gold was considered a divine metal, and many noblemen went into the afterlife with gold wreaths on their heads, gold masks on their faces, and a multitude of gold jewellery and wine cups, along with richly decorated helmets and greaves. Some of these were made by Thracians master craftsmen, others were commissioned from the best Greek artisans, living far from Thrace.

Visiting two museums in Sofia is the easiest way to see these marvels of the ancient craft. In the treasure room of the National Archaeological Museum lies one of the most fascinating finds Bulgaria has ever produced. The Valchitran Treasure is a collection of 13 gold vessels weighing 12.5 kg, made in the 2nd millennium BC, about the time of the Trojan War. The National History Museum is home to the exquisite gold drinking vessels from Panagyurishte and the delicate harness decorations from Letnitsa, with scenes from Thracian cosmological myths.

A gold mask, supposedly of Thracian king Teres, was discovered in an otherwise unremarkable grave in 2001, in the Valley of Thracian Kings

Regional museums are worth visiting, too. The Vratsa Historical Museum exhibits the amazing Rogozen Treasure, the largest ever found in Bulgaria, and the museum of Kazanlak also has a fine collection of treasures excavated from nearby tombs.

The Thracians left a trace in Bulgarian folklore and Christianity. The legendary folk hero, Krali Marko, who rides a magical horse, is probably a late Mediaeval reincarnation of the Thracian God Rider. The fairies who, in Bulgarian folklore, rule over nature and vegetation are probably faded memories of the Thracian Great Goddess. Even some saints have been influenced by the ancient Thracians. St Trifon Zarezan, for example, who is the patron of wine and viticulture, is the Christianised heir of Dionysus himself. The famous nestinari dances on live embers, which can be seen only in the Strandzha and are on UNESCO's Intangible Cultural Heritage list, are also a relic of Thracian times. They are the Christianised version of ancient rites and rituals dedicated to the Great God and the Great Goddess.

All of these make Bulgaria, with its rich and vibrant Thracian past, a must to explore.