A Roman spa buried deep beneath the City of London.

This one has sailed five times as far as Sir Francis Drake's famous ship.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

Tucked away atop a quaint Alabama pharmacy is this tiny display of antique medical tools.

An ancient cave system in Tennessee’s Appalachian foothills converted to a 1,200-person music venue.

A frozen oasis lies beneath the scorching New Mexico desert.

The official atomic museum of the United States explores the explosive and productive history of a much maligned energy source.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

A cave's rare beauty held a cavernous secret hidden underground.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

This is one really big nut.

Cockatoo Island is a Heritage-listed island in the middle of Sydney Harbour.

Ninety years of Sydney buses under one roof.

Come for the flowers, stay for the bats!

A rare specimen of an iconic extinct animal in downtown Sydney.

This rare effigy of the author spent years lost in storage.

The largest copper mine in Arizona, this enormous open pit emerges from the hills like an alien landscape.

A historic hydroelectric power plant serves as the unusual backdrop for a public park.

This 47-foot chile pepper sculpture welcomes Scoville heat unit obsessed tourists to the Big Chile Inn.

High in the Sacramento Mountains, a facility dedicated to studying the sun.

This public square capitalized on a single Eagles reference to bring some life back to an Arizona town.

Erosion and various mineral deposits give this striking canyon its distinct color and soft appearance.

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.