The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

Tucked away in the Leiden city hall are a group of works by famed artist MC Escher.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

A Nesting Doll of Churches.

Architectural monsters are devouring this palace's every door and window.

2300-year-old Roman road connecting the empire.

Architectureal fantasy quarter of Rome.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A 16th-century horror show built in a lovely Italian garden.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

The main gates have been locked since 1745 and will remain so until the Stuart Dynasty returns to the throne.

A scattered trail of street art adds a pop of color to the city's stark structures.

A secret garden in a picturesque Edinburgh village has inspired artists for centuries.

Early Medieval stones sit on display at the beautiful Govan Old Church in Glasgow.

Hidden in a Scotland museum is a copse of extinct tree stumps.

Possibly the oldest living thing in Europe, more likely a pagan survivor.

Ruined castle with subterranean vaulted Goblin Ha' or "Goblin Hall."

A 18th century graveyard and its astonishing cortege of macabre iconography.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

This castle was established by the 4th Duke of Montrose and is connected to the Buchanan Clan.