A Brutalist monument and "sculpture that contains many sculptures."

The facade of this 16th-century building is decorated with carvings of 300 seashells.

An unusual but excellent display created in the 1930s as propaganda against the Freemasons.

A hidden medieval crypt where a famous legend says the devil used to teach black magic.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

A hidden three-foot-wide house separates these two regal churches.

Eat the ultimate iteration of Portugal's most beloved pastry.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The world's oldest bookshop still in operation.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

This 11th-century fortress is now the seat of Aragon’s state legislature.

The world's largest sundial can cast a shadow more than 1,600 feet long.

A statue of a boy looks up at where the famous rival to the Leaning Tower of Pisa once stood.

Giant topiary dog once played a role in a terrorist bomb plot.

This 19th-century fountain's namesake animal isn't what you think it is.

A miniature statue of a beloved character from children's literature.

The site of Stockholm's last public execution.

This hole formed by a glacier is the largest and best-preserved of its kind in Stockholm.

Sweden's first nuclear reactor, R1, can be visited 25 meters underground.

A nightly tradition fills the streets of Flogsta with a collective scream.

The suspected burial mound of legendary Viking Björn Ironside.

A medieval church that contains murals from famed artist Albertus Pictor.

A collection of trees from various corners of the world call Stockholm University home.