A modern mechanical planetary system, part of a 10,000 year clock.

The remains of a 12th-century chapter house in Golden Gate Park.

Memorial to the father of the Republic of China.

Monument to a suicide protesting the Soviet invasion.

Macabre astrological automaton clock dating to the late 1400s.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Hindu temple of the dead home to hundreds of long-tailed macaques.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Recovered from the brink of extinction, at home in the Financial District.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

A moving memorial to the fallen and missing from WWI trenches.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

A terrific purveyor of natural history objects and curios.

Tucked in the back of this amazing antique store is an important piece of medical history.

Breathtaking and huge 430 year old maps of Italy.

These subterranean storage areas hold emergency water reserves.

Fortified medieval tower house with lovely roof garden.

The haunting ruins of Jack London's dream house.

The final resting place of New Orleans' most famous voodoo priestess.

A house filled to the brim with oddities and curiosities.

A wall of chewing gum moonlights as collective art.

Statue of Lenin, from Cold War era Czechoslovakia, now in a neighborhood of Seattle.