The world's only flying boat museum honors a small Irish village that sent 20th-century aviation to new heights.

Petrified footprints of one of the very first vertebrates to walk on land.

This ancient Irish landscape boasts hundreds of legendary ruins.

This unique railroad museum secretly contains the history of Poland rebuilding itself from the inside-out.

This open-air museum was originally a World War II testing ground for German missiles and rockets.

What was once an underground Nazi city is now Europe's largest bat reserve.

A memorial to the beloved brown bear that served in the Polish army during World War II.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

An abandoned Nazi explosives plant founded by the inventor of dynamite is now an underground museum.

The site of the first battle of World War II.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

This fortress was designed to prevent a Nazi invasion but was never used.

This Czech military museum is home to pink tank that was once a symbol of art and political rebellion.

Bullet holes in the church wall are a reminder of the violence that followed the assassination of a high-ranking Nazi officer.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

An impressive display of ships and artifacts from the ancient Mediterranean maritime trade.

Giant wind turbine with observation deck at the very top.

Retirement home for giant obsolete machines.

Walk or bike along a narrow strip of Belgium sandwiched by German territory.

A rare example of World War I trenches from the British front.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

Elaborate series of tunnels where traces of mass suicide are still visible.

The seat of the lost Ryukyu Kingdom has survived numerous fires and wars over the centuries.