A former imperial sea-fortress and Soviet prison.

The oldest church in the Estonian capital is home to over 100 fantastical cemetery coats-of-arms.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

This curious building hides eclectic details like medieval gargoyles alongside naked angels and Art Nouveau mosaics.

The secret medieval communication system will whisk your words above the noise of the crowd.

Pilgrimage site for star-crossed lovers.

A whale rib was used to advertise the store by the arch that offered exotic goods from far away.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

Ancient serpentine sacrifice holder that has stood the test of time.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A fountain standing as a testament to a doomed alliance.

A marvel of Byzantine engineering under the streets of Istanbul.

It houses the remains of a 17th-century version of the Titanic.

If there is one thing you don't want to be in Sweden during Christmas, it's a Yule Goat.

One hundred years ago this small house in downtown Zürich became the birthplace of the Dada movement.

One of a series of no-purpose kinetic artworks by Swiss sculptor Jean Tinguely.

The alpine falls where Sherlock Holmes apparently met his demise can actually be visited.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Old Tudor home moved on thick iron rails to a new spot.