An ancient capital city that dates back 3,000 years old and harbors many surprises.

Every equinox this Maya pyramid puts on a spooky ancient light show.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

These fantastically named natural pools look like something out of a Scottish myth.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

A spiral staircase connects the limestone cave with Pembroke Castle, birthplace of King Henry VII.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

The resting place for anonymous victims of the Danube's dark waters.

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

Skeletons dressed in extravagant 18th century royal costumes cavort in the aisles of this German basilica.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

The mystery of the Putim Ossuary involves a tricorn hat.

Thirty creepy ghosts now inhabit this decaying 14th-century church.

Underneath this small church are 15,000 bones, arranged by an obsessive academic.

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

The ruins of an abandoned crematorium haunt an eerie deserted German cemetery.

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

This Tang Dynasty behemoth is the biggest Buddha in the world.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The world's oldest rose is so tough it survived being bombed in World War II.