The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A wondrous old library overlooking the nation's capital.

Home to items never before seen by the public.

The site of the climactic scene from the classic horror film is now a historic landmark.

The United States Capitol's former columns still stand.

The world's largest outdoor organ is played weekly by one of just two civic organists in the U.S.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."

San Diego's most historic and haunted home.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

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

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

A marvel of Byzantine engineering under the streets of Istanbul.

This 14th century wine cellar is home to the oldest barrel-stored wine in the world.

There has been an astronomical clock on this spot since the 14th century.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This beautifully restored fortification kept the city safe for centuries.

This bazaar is one of the oldest in the Arabian world.

This spectacular mosque houses the second-largest chandelier in the world.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

Legend says this sacred tree was a gift from goddess Athena.