An abandoned mining complex in Serra do Gerês.

A small but charming botanical garden that contains many exotic plant species.

An early Portuguese serial killer's head is alarmingly well preserved in a jar at the University of Lisbon.

Perhaps the most spectacular grotto along the Algarve coastline.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

A submerged village appears when dam levels drop.

A walk down memory lane in the heart of one of San Francisco's most notorious neighborhoods.

Over 315,000 preserved amphibians and reptiles in jars.

Radioactivity still cause for concern at this urban explorer's paradise.

This partially buried wreck is one of the most complete of its kind but is only revealed when the sea allows.

Invisible bridge parts the waters, invoking biblical images and preserving the ominous feel of an ancient moat.

According to this bar, God gave an “11th commandment” to Antwerp: Thou shalt drink beer.

To enter this cluttered-yet-cozy sanctum of Belgian brews, ring the bell and tell the gatekeepers you've come “to taste beer.”

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

This museum is housed in an unassuming building that witnessed one of the most daring feats of satire in modern history.

Nature is slowly overtaking this disused cemetery on the outskirts of Brussels.

A collection of weird and wonderful art fills a former houseplant nursery.

This museum is filled with an eclectic collection of unique inventions.

A Cold War command center is hidden under an idyllic countryside.

In an area where the remnants of WWI are discovered on a regular basis this preserved frontline trench may be the most amazing.

This former Masonic lodge has been transformed into part museum, part bar, all awesome.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

A popular European tradition makes its way to the states on one of America's most famous bridges.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.