Hidden in an Italian forest is a completely homemade amusement park that has taken a lifetime to create.

These azure waters were thought to lead to the Mayan Underworld.

Abandoned power station once home to a squatter community, now being developed into an arts center.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

The flower-shaped temple in Virginia aims to transcend the boundaries of the world’s religions.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

Gnarled canopies of pink and purple wildflowers arch over the trail to the summit.

The history of radiation is on safe display at the foot of a radiation science laboratory.

Railways may have forged this quintet of lovely tunnels, but now they are open to hikers.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

A striking 12th-century-style castle built on the edge of a cliff.

Giant origami sculptures tucked into desert scenery beckon passers-by to explore further.

Prehistoric animals decorate this popular outdoor park.

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

A common entry point to the Griffith Observatory trail holds its own wonders.

A subterranean shelter remains intact under a busy Paris railway station.

By day this New Orleans square is for pedestrians, but by night it is a kingdom of kittens.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

This massive redwood tree has a hole in the base big enough to drive through.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

The largest permanent Monopoly board makes one of the longest games even bigger.