This quarter-mile tunnel under the Bluff in Pittsburgh bends at a 45-degree angle.

The last funhouse of its kind, where guests enter through the mouth of an 80-year-old blue whale.

This historic Pittsburgh tennis complex is a rare example of natural red clay courts.

Color-coded signs direct drivers on a network of routes designed to avoid Pittsburgh traffic.

Sections of the iconic limestone columns have been left uncleaned as a reminder of the city's polluted past.

The last street in Pittsburgh that's paved with wood.

An 18th-century Catholic church converted into an eccentric temple of music and bacchanalia.

The residents of the Neighborhood of Make-Believe live without much fanfare within the Pittsburgh Children's Museum.

The world's longest outdoor covered escalator system transports commuters through Hong Kong's hilly terrain.

A colossal floating restaurant built to look like a ancient Chinese imperial palace.

Taoism, Buddhist and Confucianism are all represented in this temple that claims to answer anyone's wishes.

Climb to the top of the world's largest seated bronze Buddha.

Home to items never before seen by the public.

A gift to the children of Boston, this bronze bear represents playfulness, a spirit of love, and the warmth of big hugs.

The world's largest piece of copyrighted artwork.

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

This popular Boston haunt is reminiscent of a time gone by, when slow cafes and sweet-smelling smoke wafting from patios was the norm.

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

This landmark cemetery in Boston was created more than 300 years ago.

Ice cream stand, snack bar, and time capsule of milk conveyance.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

The site of Paul Revere's historic two lantern warning.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.