A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

Now isolated, this church was once the center of a bustling village that succumbed to the Black Death.

300 years of pharmaceutical history on display.

One of the largest barracks of the Austro-Hungarian monarchy's military is now an abandoned ruin.

Hungarian self-built castle.

This Hungarian stilt village is built in a lake that never freezes over due to the power plant that that uses it as a cooling pond.

Hungarian mummies in beautiful painted coffins.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This former insane asylum now holds a pathological anatomy museum.

The Habsburgs' royal collections of art and wonders.

An overgrown and largely forgotten cemetery lies hidden within the outskirts of Amsterdam.

A unique collection of gilded age mechanical pianos.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

The attic of a four-century-old canal house hides a clandestine church.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

A rare tour of an aristocrat's private home reveals valuable 17th-century paintings from artists like Rembrandt.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

A curious collection dedicated to human and animal anatomy and pathology.

This 1920s Dutch barge is now a floating bookstore.

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

Tombstones and enigmatic inscriptions hide within a vault beneath a popular London arts venue.

High-end antique collection housed in a centuries-old church.

This South London cemetery holds the remains of more than 15,000 people.

Hackney's newest private museum and natural curiosity shop.