The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

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

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

A 2,000-year-old Adena burial mound located along a busy street in Columbus, Ohio.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

Eighty million natural history specimens call this gargantuan museum home.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

An unassuming 13-acre park is home to over 12,000 roses.

Bison, America's national mammal, are staging a slow comeback in Ohio's prairie parkland.

Breathtaking and huge 430 year old maps of Italy.

The world’s largest Masonic temple was saved by the White Stripes.

Home to an endangered salamander, a full moon celebration, and a large spring-fed outdoor swimming pool.

A free, canine-friendly alternative watering hole near the more famous Barton Springs.

The world's tallest doric column is this Ohio monument to a naval victory in the War of 1812.

Marvel at this turn-of-the-century masterpiece that has been turned into a rather stately supermarket.

Funded by John D. Rockefeller, this is one of the earliest, and most beautiful, shopping arcades in America.

This spectacular public market has got meat, fish, vegetables, baked goods, and enough kielbasa for a lifetime.

These light, hollow rolls have been linked to Acadia National Park since the 1890s.

A simple but powerful tribute to the 20 victims of the 1692 witch trials.

The colonial home of Paul Revere during the American Revolution.

An interesting decoration on this historic site, this weathervane comes with as many legends as it does questions.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

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