Remains of the old fortification along the Western border of the USSR, now an elaborate defense museum.

Remnants of the Nazis' occupation of Denmark linger along the sand.

This World War II-era bunker is now packed with posters and props from movies and TV shows filmed nearby.

A stunning bridge that appears as if it's lunging to the shore, and has a legend of a devilish architect.

The only substantial part of Nazi Germany's formidable defensive line through Northern Italy that survives today, largely intact.

Remnants of the city's Soviet history hover over this modern fast-food outlet.

The apartment building where JFK's assassin lived after defecting to the Soviet Union.

A wonderfully preserved example of London's 1960s-style high-density, low-rise public housing.

The first (but not only) upside-down house in Germany.

What started as a way to address damp basement walls turned into a house filled with intricate hand-carved designs.

One of the last examples of Soviet architectural propaganda has a few technological tricks up its sleeve.

The last fully functional fortress of Germany's World War II Atlantikwall.

This giant boulder is pinched over a 1000-meter abyss by two mountains.

An abandoned lighthouse awaits its destiny: being buried under shifting sand.

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

A line of disused military bunkers built to defend against Nazi invasion lies hidden on the outskirts of the city.

This former Soviet military base has over 10 original aircraft and an enormous amount of memorabilia on display.

Five soviet prisoners of war were executed at this spot just days before the liberation of Norway.

Where commuters walk through remnants of an ancient Greek necropolis.

One of the greatest collections of coins in the world is housed in the former mansion of an archeological pioneer.

Preserved portions of Athens's ancient defenses are on display in a subterranean parking garage.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

A crushed gate and giant bronze head serve as a reminder of Greece's fight for freedom.

Scars of this building's past life as a violent prison still cover its walls.