One of Amsterdam's narrowest houses is located right across the canal from its widest.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

A beautifully eclectic mix of architectural styles.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

One of the most iconic neon ads of former East Germany.

This incredible stone temple is a monument to death, victory, and fantasy architecture.

You can crawl inside this atmospheric 5,000-year-old tomb.

The largest stone circle in the world has ended up bringing up more questions than it has answered.

It's possible to walk inside one of the largest Neolithic tombs in Britain.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

A living memorial to the trees London lost during the Great Storm of 1987.

The home studio one of Britain's first independent record producers is also the site of a murder-suicide.

This lush area was the site of extensive enemy bombing during WWII.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

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

This marine reptile was discovered by one of the 19th century's greatest fossil hunters.

The handiwork of a underdog clockmaker who solved an impossible problem for an Empire, and forever revolutionized seafaring.

Installed at a chaotic intersection, this gave London traffic cops a place to hang their heavy woolen coats.

Lovers proclaim their unbreakable bond by leaving their names on locks fastened onto the Shoreditch fence in East London.

A famous burial ground with a history both grim and literary.

The pioneer of psychoanalysis spent the final year of his life here, still seeing patients on that famous couch.

Charles Babbage's proto-computer, painstakingly brought to life.