These small, triangular, colorful houses are a staple of Madeira Island.

This underwater graveyard commemorates a group of murdered 16th-century missionaries.

This public pool is one of the last remaining lidos of the countless built in the 1930's as public works projects in the United Kingdom.

Legend says this public grazing area hasn't been plowed for thousands of years.

An extraordinary collection of scientific instruments - and Einstein's chalkboard - inside the world's oldest purpose built museum building.

The British monarchy's stamp collection is one of the most impressive in all of Europe revealing generations of royal nerdery.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

The Tudor-style cottage in the middle of the square is not quite what it seems.

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

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

Dedicated to the art of hunting, with juxtapositions of contemporary art.

BDSM, 1930s Style.

A massive tribute to Estonian history and culture.

Dedicated to the untimely death of American balloonist and parachutist.

An abandoned bear enclosure from a 19th-century zoo located in a Danish forest.

A World War II structure that has stood the test of time.

The artwork commemorates the many ways 20th-century people perished while on the clock.

This natural wonder is disappearing at an alarming rate.

One of the largest cat sanctuaries in North America is considered a "Club Med" for felines.

The temple that withstood the Nazis.

A striking symbol of the Bulgarian capital.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.

Ancient and modern architecture are joined in Louis Kahn's monument to democracy.

This historic textile city was abandoned after being ravaged by fire.