The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

An abandoned boat that's been stranded mysteriously for decades.

Abandoned ships along a deserted beach feel like the set of a post-apocalyptic thriller.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

This 8th-century Bavarian monastery is home to an exquisite Baroque-era library.

3,000 market stands in five former Zeppelin hangars.

Flamboyant architecture from the turn of 20th century.

A black cat protests the City Guild in Riga's Old Town.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

The remains of a remote village that once housed over 1,200 dam workers and their families.

This nearly abandoned "company town" is a ghost of Puerto Rico's once-lucrative sugar industry.

An abandoned village that resides along the mountains of the Aosta Valley.

This small collection of rare books was uniquely locked up for safe keeping.

Chelsea's soldiers were given strict orders when crossing this historic bridge.

This elaborate tunnel is the first structure composed of cast concrete in the United States.

One of Vietnam's most iconic landmarks was built by Japanese traders and is now in danger of sinking.

A statue erected on an infamous cliff where young boys would hold dangerous "pee offs" to prove their mettle.

High in the mountains of Kochi Prefecture, a magnificent library designed by a world-famous architect.

The city of Manchester quietly unveiled this tribute to a 19th-century massacre.

An abandoned canal route lies hidden under the streets of Manchester.

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

Manchester's abandoned train depot lingers in a post-industrial purgatory.

This nondescript building hides an entrance to an underground nuclear tunnel system.