This place radiates a magical energy to many. It is still unclear why people erected the structure some 4,500 years ago: Was it a temple, a coronation site or an observatory for the sun? Stonehenge continues to cast its spell, with tens of thousands of visitors making the pilgrimage to the site every year, especially for the winter solstice.

About 500 years before Stonehenge was even erected, people built the Ring of Brodgar on the Orkney Islands, around 3200 B.C. The site features a huge stone circle that is 104 meters in diameter. Today, 27 of the original 60 boulders are still standing. Did these ancient builders later export their knowledge to Stonehenge? And was this ring also used as an astrological facility? No one knows.

These megaliths were also placed on one of the Orkney Islands around 3100 B.C. Archaeologist Nick Card believes that this was "an important site" some 5,000 years ago. He and his team have been excavating sites on the islands for years, and have now reconstructed 20 houses that once stood there. Card believes that people did not live here permanently, but came to hold festivities together.

The Carnac stones are 7,000 years old and continue to fascinate people today. About 3,000 standing stones ranging from 0.5 to four meters in height have survived for centuries. It is said that even Caesar's legionaries were amazed by the structure that stretches out for four kilometers. Did they serve as a place of assembly? Or was this a place of pilgrimage? That remains a secret.

This complex near Kaseberga is often called "Sweden's Stonehenge." However, this constellation of stones is not actually a circle: 59 stone blocks are aligned here in the shape of a ship hull that is 67 meters long and 19 meters wide. Archaeologists assume that Ales Stenar served as an ancient burial place some 1,400 years ago. The site attracts about 700,000 visitors every year.

Near the Swedish village of Bohuslän, there are another 100 or so stone circles and graves that were first laid out during the Iron Age. From this burial ground, you get a broad view over the nearby North Sea. Researchers believe that the site was still in use as recently as the Middle Ages, as a meeting place.

These stone relics of an earlier culture were uncovered in the remote Katun Valley of Russia's Altai Mountains. Some of the rocks feature prehistoric engravings. Scientists suspect that this was a sacred place of worship, which — similarly to Stonehenge — was probably also used for astronomical purposes.

There are four stone circles in the middle of the forest near the German village of Boitin. According to a legend, a wedding took place here once upon a time. The party went a little out of hand, with the wedding guests treating their food without respect, throwing bread and sausages around in their merriment. The gods then turned them into rocks.

These six preserved megalithic tombs near Lüdelsen in Saxony-Anhalt date back to the Neolithic period. Together with about 50 other preserved megalithic tombs in the region, there are plans to build a 40 kilometer-long "Megalith Route Altmark" to attract tourists.

Residents of Chile's Easter Island, which is located in the middle of the Pacific Ocean, call these statues Moai — which translates as "stone figure." Researchers date the 900 monuments back to between the years 1250 and 1500, and many assume that they represented chiefs or ancestors, who were believed to act as a link between this world and the next.