Commemorating the spot where the famous scientist fed his pigeons.

The fairy tale castle of the "fairy-tale king."

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The prototype for all Nazi concentration camps.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

An enormous, inside-out glass globe built in 1935.

Ice cream stand, snack bar, and time capsule of milk conveyance.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

This massive tea kettle was once a promotional stunt for the Oriental Teashop.

World's first "penitentiary," meant to be humane, drove men insane.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Rummage through this sunken ship, but leave your scuba gear at home.

Ride the subways of yesteryear.

An artist's cute bronze subway sculptures belie his violent artistic past.

Elevated freight railway turned wildly successful urban park.

The most confusing clock in New York.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.