Despite the name, this ancient piece of crystal may not have been a lens at all.

This small chapel built into rock is the oldest place of worship in Luxembourg.

One of Ayutthaya’s most iconic locations is a mysterious, hauntingly surreal miracle.

The longest staircase lock in Britain.

The official motto of Luxembourg reminds passersby of the Luxembourgish commitment to their national identity and sovereignty.

The grave of the famous painter is marked by a simple stone in the ground.

A totem pole of heads to represent the different stages of life.

A plaque on the base of this statue holds a bewitching design.

This little sun pays homage to a massive gate that once stood at this location.

This modernist bridge highlights the bear as a symbol of Madrid.

The oldest Anglican church in Southeast Asia.

One of the oldest and largest wooden churches in France was very evidently constructed by shipbuilders.

Germany's longest suspension rope bridge.

This pair of unsuspecting buildings are in fact the very first modern skyscrapers in Europe.

A memorial for public executions that dates back to the 14th century.

Once a resting spot for King Fernando VII.

Dedicated to the Father of the British Fire Service.

A must for film lovers in Madrid and home to the Spanish Film Library's projection space.

In this 400-year-old hotel in Madrid, you'll find a comb in every room, an old clock, and maybe a ghost.

Local folklore claims that this wall was not built for defense, but to provide labor during a time of famine.

This cryptic monument honors a mysterious dead woman, despite her identity being lost centuries ago.

A pair of giant stone heads represent the ancient Roman saints beheaded here.

Meant to resemble a massive tree, the building is the best example of Spanish organicist architecture in Madrid.

In the heart of Luxembourg's "little Switzerland" weaves a breathtaking natural sandstone canyon with a mythological past.