The world's oldest individual clonal tree looks like a wimp despite standing tall for 9,550 years.

A floating underwater hotel, created by a Swedish artist.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

Stockholm's deepest subway station is also a stunning ecological wonder.

The library's graceful rotunda is like a bibliophile's temple.

This pedestrian walkway cuts through a cemetery and over several burial vaults.

The castle still holds traces of the abandoned Roman fort it was built atop.

A tiny village in Wales claims the name of a noble medieval hound slain for a crime he didn't commit.

Picturesque ruins once held off mighty armies.

A real-life Professor Snape once taught in this Welsh university building, which students of course nicknamed “Hogwarts.”

Welcome to the world's only museum dedicated to the Ukranian Easter egg.

340-foot statue built to honour the Heroes of the Soviet Union.

The largest catacomb system in the world.