A rare example of an octagonal Catholic church.

A town saturated in Italian rationalist architecture was once marshland drained by Mussolini.

The remains of Crystal Palace Great Exhibition of 1851.

The final resting place to 300 Victorian-era pets hides inside the city park.

This abandoned Swedish folkpark offers an amazing view over the town of Överkalix.

A well-restored ancient archaeology site gives a real feel for life during the Roman age.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

Remnants of a Victorian garden feature sitting in public woodland.

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

This tangled English forest looks like something right out of a fairytale.

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

The signs of a long buried road can still be found hidden beneath a London sewer grate.

An ornate Thai pavilion in the middle of Sweden.

This cobblestoned medieval-style town was entirely constructed in the 1990s and 2000s.

This amazingly preserved Doric temple was abandoned before it was ever completed.

This Torino museum honors a soldier who kept the city safe using barrels of exploding gunpowder, losing his life in the process.

A 16th-century Andalusian palace.

Wonderland replication in progress by one persistent man.

An exact replica of a colossal Olmec head sits atop a pyramid within a Madrid traffic circle.

An outsider folly near Madrid.

Stuck in the middle of a modern Madrid city block are the remains of a 19th century sports complex.

Rainwater transformed this old quarry into a peaceful pond you won't find in most tourist books.

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