Mysterious craters may have been home to an ancient cult.

This Latvian shot factory is still used twice a year to manufacture bullets the old-fashioned way.

This former Nazi labor camp is now a poignant memorial, complete with giant Soviet-style monuments.

This ornate church has survived Nazi and Soviet occupation, including a short stint as a Soviet-era gymnasium and cinema.

This impressively complicated radioastronomy research center was once a tool of Soviet spies.

Built to ward off Napoleon's army, this city-sized abandoned Russian fort is now perfect for urban exploration.

This charming Latvian lane doubled as Baker Street on the Soviet Union’s version of Sherlock Holmes.

The mile-long pier stretches from a ruined fortress out into the Baltic.

Guests become prisoners on a visit to Latvian prison.

The reconstruction of this prominent building fulfilled a long-written command.

A top secret Cold War bunker hidden beneath a Latvian spa facility is now open for tours.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

These crumbling Latvian forts make for some haunting seaside ruins.

A black cat protests the City Guild in Riga's Old Town.

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

The oldest housing complex in Riga is a mini timeline of architectural trends.

Flamboyant architecture from the turn of 20th century.

The world's first invisible city square is an homage to a man who pushed the boundaries of art.

An extensive collection of some of the oldest grave markers in Lithuania.

A century-old prison in the heart of Vilnius is now a lively bar, dance club, and artist residency.

The pyramid and dome deep inside the Dzūkija forest are believed to channel divine energy.

Over time, this castle grew to encompass the entire island.

This former KGB building is now a museum memorializing the people who suffered during the Soviet regime.

Open-air museum with a large collection of Soviet-era statues.