Oldest building in Rome

Of the original Seven Wonders of the Ancient World, only one wonder still exists today: the crumbling, gorgeous Great Pyramids of Giza. But there are plenty of other ancient structures that deserve our attention too, from a 2, 000-year-old church to a more than 1, 000-year-old Buddhist temple that's made out of timber. Even more remarkable? All of these building are still in use. Check out 17 of these tributes to human engineering, below.

The Colosseum once regularly hosted fifty thousand Romans, eager to witness the blood and violence of the legendary gladiators. Because of its ruined state, these days it can only hold a few hundred people on temporary plastic seats for (horribly overpriced) cultural events. Larger concerts and Roman Catholic events are also held outside, using the Colosseum as a dramatic backdrop.

Photo: Franco Origlia/Getty Images

Likewise, the Church of the Nativity (565 AD, Bethlehem, West Bank) is one of the oldest church buildings in the world—today, it still hosts multiple church services every day.

Photo: Nadav Neuhaus/Getty Images

The Proserpina Dam (Merida, Spain) dates from the first or second century AD, and once fed the Roman aqueduct taking water to a nearby city. This ancient Roman gravity dam is still used by local farmers to irrigate crops.

Photo: JMN/Cover/Getty Images

Most of the thousand-year-old temples in Angkor, Cambodia, still serve religious function among the locals.

Photo: Attila Nagy/Gizmodo

The ancient Stonehenge is still a place of religious significance for Neopagan and New Age believers, and particularly for the Neo-druids.