Throughout this shopping mall are medieval ruins that were discovered during the mall's construction.

Looming communist pillar with a Czech twist.

The deepest sinkhole in Central Europe comes with a grisly tale and an unusual nickname: “The Stepmother Abyss.”

Instead of sermons, this church became home to millions of books.

A striking, modern church devoted to a nun who loved God and beer.

This man-made mound monument was built out of soil from all across the Polish empire.

The bones of the Biblical Magi traveled to Constantinople and Milan before landing in their current home inside an elaborate golden reliquary in the Cologne Cathedral.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

This coffee shop lies hidden beneath a historic church.

A measuring mishap led to these artificial stone ladies losing their stomachs.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

This sculpture encompasses the emotion of rail travel.

This open-air mosaic gallery honoring an English artist took hundreds of volunteers more than seven years to create.

A closed London rail station created to cart away the dead still bears the marks of attempts to make it less morbid.

A hands-off space for graffiti artists to hone and display their skills.

The anatomical-pathological collection of a man who changed surgery.

An unusual round church in London with a Templar past.

At the center of London’s oldest roundabout stands an obelisk that was erected in 1771, but spent several decades elsewhere.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

Remnants of a Victorian garden feature sitting in public woodland.

This 1920s Dutch barge is now a floating bookstore.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

This public park collects signposts and other memorabilia related to local history, Polish-German relations and human progress