One of Scandinavia's largest mosaics pays tribute to Danish art and science luminaries.

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The beautiful baroque library of the Hapsburg empire.

This crumbling medieval basilica once attracted pilgrims by the thousands to collect a miraculous dust that formed above the saint's tomb.

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

This ratty natural history collection is a charming relic among a city rushing into modernity.

Thirty architectural gems from the 19th- and early 20th-century Tokyo were restored and relocated to this space.

A fifth-century temple improbably built into the side of a cliff.

This short pedestrian span is also known as the "Fairy Walking Bridge" because it looks almost magical.

Ring the bell to enter a bar that looks equal parts museum and old curiosity shop.

Canada's largest dinosaur skeleton was hidden away in storage for more than 40 years.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

A medieval weapon rumored to have been used by the brilliant poet himself.

Drink wine handed out through a window as part of an age-old tradition.

An extraordinary collection of 18th century anatomical waxworks.

This historic abandoned train station looks like a stop for ghost trains.

The abandoned funicular tunnel was a secret base for the BBC during World War II.

Street artists transformed this abandoned industrial neighborhood into one of Europe's largest graffiti exhibitions.

Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

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

The largest and most famous wax anatomical collection anywhere in the world.

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.