In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

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

The world's longest known cave system.

The world's largest collection of mechanical puzzles is a cornucopia of analog bafflers.

Dozens of padlock-trees along the Moscow River.

Former headquarters of the KGB.

World's largest bell sits on the grounds of the Kremlin in Moscow.

One of the oldest and certainly best preserved Cistercian abbeys still in existence.

Stonehenge has nothing on Castlerigg’s views.

A six-ton wedding present for the King of the Scots.

The most loyal of little dogs, or a Victorian era publicity stunt?

Largest lake in Great Britain measured by surface area.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

A small island abbey is the final resting place of many medieval Scottish monarchs, including the real Macbeth.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

It houses the remains of a 17th-century version of the Titanic.

A walk through the historic city center, under the streets of Seattle.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

The private clubhouse for the members of the Academy of Magical Arts.