No one really knows how these old hobby horses got here, but the herd keeps growing.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

The only surviving building of historic West Boylston, which was flooded to create the Wachusett Reservoir.

An eccentric Victorian aristocrat's enormous collection of medieval armor and weapons from around the world.

This coffee shop lies hidden beneath a historic church.

This general store near Boston was once owned by Henry Ford, who had it relocated to a different town using a team of oxen.

Once the largest gravity dam in the world.

Residents of Berlin take their coffee and cake in one of the city’s most restful spaces: a cemetery.

One of the oldest cemeteries in Germany was originally used for victims of a cholera epidemic.

This metal eagle one of the final remnants of a newspaper that wanted to keep Brooklyn to Brooklyn.

This outdoor gallery of sculptures along the East River was once a landfill.

Hamburgers are intensely proud of their tunnel beneath the river.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

This monumental work of art symbolizes the coming together of a previously divided city.

Try not to get slimed in Tribeca.

Super-heavy Nazi architectural experiment.

A towering monument to war, located on a beautifully peaceful hill.

For patriotic Russians, this memorial honoring the Soviet soldiers who died liberating Berlin in 1945 is the most sacred location outside of Russia.

This miniature village stays behind in the Breuer Building, even as the museums around it come and go.

A grassroots community effort in the 1970s led to the creation of this beautiful garden full of delightfully whimsical exhibits.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

An abandoned swimming pool decays on the outskirts of Berlin.

This sculpture forces visitors to confront their relationship with space.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.