Locals say the water level in this 1,200-year-old tank never goes down.

The world's second-largest sundial, made entirely out of stone.

The remains of what was, not so long ago, the world's largest city.

An ancient monastery, a locked room, and a mysterious book heist.

You can climb to the top of the world's largest rocking horse.

The oldest military monument in the United States.

This propitious plastic porcine has been petitioning park visitors to pick up after themselves for more than 50 years.