An ancient instrument used to measure the waters of the Nile so Egyptian farmers would know whether to expect famine or flood.

A roadside spring pooling in an old bathtub where anyone can stop and sip.

The world's oldest bookshop still in operation.

Meant to be one of the most extravagant hotels in the world, now an eerie, abandoned architectural gem in Mexico City.

Home to what locals claim is the largest whale skeleton in Southeast Asia, which is worshiped yearly.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

The island where one woman reigned as a "queen" over 30-odd Japanese soldiers who refused to believe that WWII had ended.

The historic cave is both a symbol of superstition and black magic and inspired one of the early Christian converts in Botswana.

This 14th century wine cellar is home to the oldest barrel-stored wine in the world.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

These beautiful ruins deep in the Pennsylvania woods are thought to have been a ski lodge or a speakeasy, but no one really knows.

The cave where two British judges hid in exile after sentencing the king to death.

Inside this small brick bungalow is a collection of toys intended for the afterlife.

One of the world’s most colorful cemeteries, where each pigment is symbolic.

This Upper East Side apartment co-op was designed as a tuberculosis sanitarium.

An unusual bronze bus shelter is actually an art installation commenting on the city's history with the Nazi party.

An impressive display of ships and artifacts from the ancient Mediterranean maritime trade.

A big museum full of little worlds.

This rare volcano spews the strangest and (literally) coolest lava in the world.

The whole world in one water tank.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

A rare wayfinding portmanteau of “Street” and “Avenue.”