Two volcanic lakes in an enormous crater formed in a prehistoric eruption.

Eighteenth-century home, where Herschel discovered the planet Uranus.

An incarceration museum on the spot of possibly the oldest prison in England.

Where Stoddart and Connolly suffered in the infamous Bug Pit.

An unused hyberbolic electricity pylon kept as architectural monument.

At the very tippity-top of Europe is a cliff from which you can view the midnight sun.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

Secret Soviet city once home to Russian cosmonauts and space training facilities.

The deepest hole drilled in the name of science, where evidence of Precambrian life was found.

This massive glowering Lenin head gazes out over eastern Siberia.

Some of the world's only freshwater seals live in one very special lake in Russia.

A tiny park off the beaten path covered in ingenious scrap metal sculptures.

The Uyghur settlement in the middle of a lake continues to raise questions.

Home of Vissarion, the "Jesus of Siberia."

Unusual, mushroom-like rock formations caused by weathering and water erosion, set to disappear, according to geologists.

One of the most horrible legacies of the Cold War is a site where the Soviet Union tested nuclear bombs on civilians.

Iconic pyramid from famed British architect Norman Foster designed to represent all of the world's religious faiths.

An entertainment center in a huge transparent tent.

An abandoned Soviet-era park that, when viewed from the air, looks like a pentagram.

Rusting ships sit in a desert where a sea used to be.

World's oldest and largest space launch facility, once a secret missile testing site.