A striking symbol of the Bulgarian capital.

This San Diego museum, housed in a former Navy training facility, is dedicated to preserving women’s historic achievements.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

The artist and New York City icon lived, worked and died in this converted carriage house owned by another iconic artist, Andy Warhol.

With statues of Nelson Mandela and Harvey Milk this monument has been called the Mount Rushmore of California.

An Adirondacks museum housed in the former studio of Marcella Sembrich, the 19th century opera star most famous for her role of Mimi in "La Boheme."

An inconspicuous footbridge beloved by San Diego locals.

This castle-like building in Manhattan helped destigmatize cancer in the 19th century.

Tiki luxury on Nob Hill.

This Latvian shot factory is still used twice a year to manufacture bullets the old-fashioned way.

Elvis's own personal tropical hideaway.

A notorious Route 66 eatery once frequented by Al Capone.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

Where the "World Pinball Champion” is crowned.

A painted-over wall in Detroit originally built to segregate a black community from an adjacent white development.

This heart-shaped island looks substantially less lovely after a recent bulldozing project.

The stone labyrinth in this New Orleans city park was laid to symbolize healing in the wake of Hurricane Katrina.

A giant telephone commemorates the last "crank" call ever made in the U.S.

This is the house that spite built.

The alpine falls where Sherlock Holmes apparently met his demise can actually be visited.

A preserved 18th century homestead in Western Pennsylvania marks the spot where the Whiskey Rebellion began.

A precariously balanced rock perches on the edge of a cliff created tens of thousands of years ago by glacial erosion.

True to its name, this bouncy walkway may be the world’s smallest suspension bridge.

The final resting place of two members of the infamous Doan gang, notorious outlaws and Revolutionary War Loyalists.