Live out your childhood construction fantasies in this one-of-a-kind gyrating hotel.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

A tiny, hidden alleyway dedicated to the father of meteorology.

Hidden on the urban banks of a Manchester river are a series of abandoned waterside industrial sites.

These lovely Turkish-styled baths were brought back to life after winning a reality show competition.

A Victorian Gothic masterpiece housing a world-class collection of rare books and manuscripts.

A 19th-century time capsule of travel, fiction, and historic texts still available to the public.

A reliquary of pop culture marvels, including the world's largest (and most terrifying) Jack-in-the-Box.

The grand, column-fronted, sculpture-adorned home of the ambitious digital library.

One man's swirling six-acre monument of stone.

Despite having a dome made of papier-mâché this tiny observatory has survived for over a century.

Have a seat with the father of modern computing at this Manchester monument.

Helped by a surprise posthumous donation this small town toy museum features over 5,000 vintage playthings.

Secret Soviet city once home to Russian cosmonauts and space training facilities.

A plaque commemorates the spot in the Oregon woods where the first-ever Geocache was hidden.

Vast network of air raid tunnels beneath Lombardy's capital.

In an arboretum with hundreds of memorials to the fallen, this one might be the most poignant.

This Italian foot path winds through the mountains via 52 individual tunnels.

A climbing route in the mountains of Italy’s Dolomites, built for soldiers during World War I.

The world's longest and deepest train tunnel.

At Macon’s oldest cemetery two members of Allman Brothers are buried side by side.

A retrofuturistic art installation in the Pittsburgh Airport.

The taxidermied remains of Charles Dickens' pet raven, which helped inspire one of Edgar Allan Poe's most famous poems.

The original "capsule building" is a masterpiece of Metabolist architecture.