The largest greenhouse in the world is home to over one million types of plants.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

At this Arctic outpost, get to know members of the indigenous Sámi community and meet their herds.

This roadside attraction looks like a flying saucer parked atop the tundra.

Thousands of years of crashing waves gave this mushroom-shaped rock its svelte figure.

A stunning silver lining to global warming's gloomy cloud.

The largest cave in Northern Europe.

The world's northernmost brewery uses water from a 2,000-year-old glacier to create its beer.

A Viking-style brewpub named for a Norse sea giant, in the heart of fjord country.

The world's largest underwater restaurant is submerged off the southern tip of Norway.

The convergence of two currents makes this a surprisingly pleasant getaway in the Arctic Circle.

This "preacher's pulpit" once used for pagan ritual, is home to a new, and dangerous ritual.

An intricately carved Viking church overlooks a glistening fjord.

Madrid's last horchata kiosk is a blue-and-white beacon of refreshment.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

A unique underground structure dating back to the 1st century BC.

A quaint medieval millhouse hovers surprisingly above the waters of the Seine.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

The 16th-century church was kept in its ruined state as a reminder of the casualties of World War I.