An abandoned railroad tunnel is now filled with bioluminescent bugs.

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

The building where Mary, Queen of Scots was said to have bathed in white wine.

In the ruins of Glastonbury Abbey lies the alleged resting place of the legendary king.

The oldest residential street in Europe also features an optical illusion.

Inside this magnificent 12th-century church is one of the finest carved wagon-roofs in all of England.

A converted cattle farm is now a hub of art and theater surrounded by nature.

One of Canada's tiniest museums tackles the world's largest turtle.

A beautiful waterfall and beach where precious stones are plentiful.

The first "applecore" style lighthouse in Nova Scotia.

The remains of an attempt to carve a thriving metropolis from the forest, and once home to the first revolving door in North America.

This historic cemetery stopped accepting bodies before many Canadian cities were founded.

Eastern Canada's ocean playground.

Enormous sandstone towers loom within a Czech forest.

The southernmost outpost of the Russian Empire in colonial America.

This alley off Edinburgh's Royal Mile contains remnants of the city's seedier history.

This historic pub has maintained much of its 1906 decor, including a small sequestered room for women, where orders were slipped through a tiny window.

A 12th-century church with a medieval fresco and an intriguing “Greek runestone.”

The verdant mossy ruins of a Franciscan monastery lie in the remote Sintra hills awaiting exploration.