Situated in modern-day Lebanon, the ancient Phoenician city of Baalbek spent a great deal of time under Roman rule. Today, the city is a UNESCO World Heritage site and is home to sprawling Roman ruins, including those of a trio of Roman temples dedicated to Venus, Mercury, and Jupiter. The Temple of Jupiter is one of the largest and most ornate temples ever erected by the Romans.

Hadrian's Wall, a UNESCO World Heritage Site located near the border of Scotland and England, is a relic of the Roman Empire's occupation of Britain. Originally built in 122 CE, it stretches 73 miles from coast to coast in England, and served as a defense of the northwestern frontier of the Roman Emperor for nearly three centuries. It was named after Emperor Hadrian, who ruled from 117 to 138 CE.

When people stood inside the original Stonehenge and spoke, the surrounding 157 stones of the original monument boosted their volume. But for someone standing outside the circle, it would be difficult to both hear and understand what was being said inside. Although the original purpose of the site remains a mystery, researchers believe that it may have been used for ritual ceremonies.

In the Taurus Mountains in Adiyaman, you’ll find one of Turkey’s most famous sites: Mount Nemrut. The giant sculptures there were made as a tribute to Antiochus I Theos of Commagene, who reigned from 70 to 38 BCE. The leader wanted his tomb to be on the same level with the gods, and had large sculptures of himself, his ancestors, and other gods built on the mountain.

The last thing you’d expect to see in the Spanish capital is an ancient Egyptian temple. But that’s what you’ll find at the center of Parque de la Montaña in Madrid. The Temple of Debod was dismantled and rebuilt there in the early 1970s. The Egyptian government gifted the temple to Spain so that the ancient structure wouldn’t be flooded by the Aswan Dam that was being built at the time.

The Lighthouse of Alexandria was one of the Seven Wonders of the Ancient World until it succumbed to natural disaster sometime in the 14th century. Believed to be more than 330 feet tall, it was one of the tallest structures of its time. Pharaoh Ptolemy I Soter had the lighthouse built on the island of Pharos in the Nile Delta, as both a symbol of his power and a guide for ships into the nearby city of Alexandria.

Built by the ancient Nazca culture around 100 BCE, the Nazca Lines are a series of massive etchings in the ground, some of which are up to 30 miles long, that can only be truly seen from the air. The Nazca people dug a few feet into the ground to create the designs, but no one is sure exactly why.

The Acropolis of Athens is one of the most significant sites from ancient Greece. The word “acropolis” translates to “high city,” but in ancient times the site was known by the name Cecropia, after the city’s mythical first king, Cecrops. According to legend, Cecrops helped the goddess Athena win the coveted title of the city's protector.

The collection of more than 7,000 life-size clay models of soldiers and their horses — often known as the Terracotta Army — lies outside Xi’an in the grand mausoleum of Qin Shi Huang, the first emperor of China. They were built as guardians to his burial site when he died in 210 BCE. The mausoleum wasn’t discovered until 1974 by a group of local farmers; today it is a UNESCO World Heritage Site.

Not only is the Pyramid of Giza the most ancient monument on the list of the Seven Wonders of the Ancient World, it’s also the only one that remains standing today. Architects and historians admire the ancient tomb for its elegant construction, colossal size, and perfect proportions — all the more impressive considering it was built between 2700 and 2500 BCE.