Roman ruins top white travertine terraces formed by ancient hot springs.

Flames have been burning within this mountain for more than 2,500 years.

An abandoned tank sits in an empty London lot as a symbolic middle finger to local city planners.

In an isolated field near a dilapidated barn stands this chilling portrayal of the plight of the Nuba peoples of Sudan.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

One of four sister bronze sculptures dedicated to the widows and orphans of an 1881 tragedy.

This lonely bronze walrus celebrates a character in a Lewis Carroll poem.

Huge winged monument in the United Kingdom.

The tallest hotel in Europe.

The alpine falls where Sherlock Holmes apparently met his demise can actually be visited.

A symbol of friendship between the mountainous regions of Switzerland and Bhutan.

A breathtaking bridge that crosses a vast gorge over a river's torrents, and has a tale of a devil architect attached.

One of a series of no-purpose kinetic artworks by Swiss sculptor Jean Tinguely.