The commemorative stone column conceals a secret laboratory.

One of Auckland's oldest cemeteries was partially demolished during the construction of a major highway in the 1960s. 

These barriers stand as stark reminders of Northern Ireland's troubled past.

New Zealand's only running funicular railway.

A half-mile-long stretch of medieval forts built after a devastating pirate attack persists amid the modern port city.

The platform atop this verdant volcano was built with the help of a royal elephant.

The longest fence in the world stretches over 3,000 miles to keep the dingoes out.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This eccentric cave dwelling is bizarre even by the standards of a subterranean town.

One of the world's steepest streets seems to have houses sliding down it.

A New Zealand communications tower stands as the tallest structure in the Southern Hemisphere.

Ming Dynasty necropolis raided during the Cultural Revolution.

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

An opal mining town in the middle of Australia where people live, worship, and shop underground.