Temple of Zeus Olympus

What I really love about ancient cities is how well-incorporated the points of interest are; there's no need to take a bus 10 km out to find the cool ruins. These remnants of a temple are right in the middle of Athens.

The Temple of Olympian Zeus

This place has a crazy history. It was completed 600 years after its construction began, having seen three (well, four, but Augustus didn't make much of an effort) different sponsors. The first was a Greek tyrant in the sixth century BC; when he was overthrown, nobody felt like continuing his work. But in 174 BC, the king of Syria took up the task...work continued until he died. The next to touch the massive project were the Romans Augustus and Hadrian.  

The temple was finally inaugurated in 131 AD, the largest of the ancient Athenian sanctuaries. It contained a gigantic statue of Hadrian, who was worshiped alongside the similarly proportioned chryselephantine statue of Zeus (new vocab word for me--chryselephantine means plated with gold and ivory.)

A violent storm toppled one of the 16 remaining columns in 1852, allowing an unrivaled view of its construction. Also, it looks like sliced cookie dough.

Worship continued in the temple for at most 300 years. After 600 years of construction.

But in any case, the people of Athens were so happy that they built Hadrian his very own arch.