This soviet pilot's graveyard is filled with headstones made of airplane fins.

This abandoned fighter jet launch center is now a haunting street racing course.

Abandoned Soviet base once stocked with short and medium range missiles pointed at western Europe.

The secret cells in the basement of the KGB's Estonian "Grey House" have been preserved as a grim Cold War museum.

This small Estonian hill is covered in hand-made twig crosses that are said to bring good luck.

Wars fought and wars won are remembered by these abandoned bunker ruins.

Man-made mineral caves house massive bat colony.

Mysterious craters may have been home to an ancient cult.

The ruins of an Estonian prison are drowning in the quarry lake where the convicts were once forced to work.

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

Formerly Yugoslavia's "forbidden island," this sleepy little city still holds the abandoned remains of military strongholds.

When Croatia became independent of Yugoslavia, the splintering governments left behind these concrete tunnels.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

The oldest church in Iceland is one of the few to feature ornate decoration.

A trio of hidden hot tubs takes advantage of Iceland's natural geothermal vents.

Climb right into the heart of this colorful Iceland volcano.

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

This volcanic cave lake is essentially hard proof that Iceland is the most magical place on Earth.

Rising from the sea like a stone monster.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

A unique museum tells the story of the day-to-day life of World War I soldiers.

This small commune with an even smaller name appears to have an unlikely amount of dead ancestors.