Pompeii's less famous neighbor is still revealing her secrets.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Outdoor art exhibition made of classic Tetris pieces.

One of Australia's largest secondhand bookstores.

Come for the flowers, stay for the bats!

This historic observatory contains the world's oldest refracting lens telescope.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

"The prettiest love letters in the world" ... or so said Lord Byron.

Pilgrimage site for star-crossed lovers.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

The Habsburgs' royal collections of art and wonders.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Twelve sculptures designed to make their best showing with the coming or going of the sun.

The miraculous hydrant that saved the Mission District in 1906.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

The ancient latrines of the Greeks, in all their public glory.