A wooden street sign is the last remnant of this 400-year-old alleyway.

The Swedish flag over this small naval fort signals that the nation is at peace.

Sound travels strangely in this underground whispering gallery.

An 11th-century runestone decorates the halls of Terminal 2 of this Scandinavian travel hub.

This gem from the industrial age helps visitors and residents alike traverse hilly Stockholm.

A king's bloodstained shirt is among the gruesome collection of artifacts displayed below Stockholm's Royal Palace.

This giant subway sculpture celebrates the fruit that inspired the theory of gravity.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

This railroad track was so secretive that it was omitted from all maps.

A former suicide bridge is now accumulating symbols of love instead of a body count.

If there is one thing you don't want to be in Sweden during Christmas, it's a Yule Goat.

This grisly exhibit houses skeletons and weapons from a devastating 14th-century clash.

The discovery of an old wall led to the creation of this fascinating museum about the city in the Middle Ages.

It was meant to help transport wounded soldiers to a secret underground hospital.

The Guardian of Tallinn.

Locals rallied to save this beloved mural after someone mistakenly attempted to cover it.

The official meeting point for the oddly named governing assembly of ancient Sweden.

The largest Chinese cemetery in the world outside of China dates back to the 15th century.

Malaysia's first and only glass temple.

A lush indoor jungle fills this bustling Madrid transportation hub.

A mysterious, hidden cluster of Buddha sculptures carved into the rocks.

Sacred Buddhist home of some spiritual monkeys.

Singapore's landscaping project is home to 18 incredible Supertrees.