The tallest tower in Cáceres's Old Town.

The largest medieval water tank on the Iberian Peninsula is preserved beneath the Cáceres Museum.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

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

From grand battles to daily life, this Spanish museum offers a view of world history in miniature.

This representation of Lord Vishnu is the largest stone sculpture in Nepal.

Nailing a coin to this holy stump is just another way to ask the gods for relief from dental pain.

This historic square in Nepal is home to temples dating back to the third century.

One of the largest Buddhist stupas in the world keeps an eye out in every direction.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

Ancient cliffs resembling a kilt on Scotland’s second-largest island emit an entrancing sound.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

360° views of the city plus five floors of optical illusions and hands-on science.

This artistic fountain display pays homage to this area's theatrical history.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

This plaza is home to a number of works, including Montpellier‘s own Arc de Triomphe.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

The way that light hits a stained glass window on a specific day is one of many "clues" to a mysterious treasure.

Historic medieval fortified city in southwest France.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

The site of the first medieval crusade that pitted Christians against Christians.