A line number in Amsterdam that will likely never be used again due to its tragic history.

The mirrored section takes the shape of Hebrew characters when viewed from above.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

Europe's official "zero-level," the equator of elevation.

The former headquarters of history's oldest megacorporation.

The world's only museum devoted to the wonders of fluorescence.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

An archway adorned with vulnerable flora and fauna.

A memorial for public executions that dates back to the 14th century.

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

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

This sculpture encompasses the emotion of rail travel.

The broken skateboards that became a poignant memorial to a murdered skater.

A faded reminder of what was once a common sight in London during the Blitz.

A tiny replica of the iconic London landmark hides on the side of the steel structure.

Catacombs turned marketplace.

The remains of an ancient Roman teenager are memorialized at the base of a modern London landmark.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

Ship-sized kinetic sculptural fantasy.

This South London cemetery holds the remains of more than 15,000 people.

This one has sailed five times as far as Sir Francis Drake's famous ship.

One of London’s rare Tudor-era buildings is a fate-defying gatehouse for a church.

The ruins of a church destroyed by both the Great Fire of London and the Blitz, now turned into a peaceful garden.