A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

The 1920s child prodigy author was last seen here at her Brookline home before vanishing at age 25.

Trinkets and toys lovingly handmade by maximum security prisoners.

Barely visible foundations remain where Stow Lake’s “observatory” once welcomed visitors.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

San Francisco's newly reopened hands-on science museum.

An vast warehouse of everyday treasures in Berkeley, CA.

The first bridge observation tower in the U.S. offers one of the best views of Maine.

This 19th century granite fortification is one of the most well preserved forts in New England.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.

A modern Nordic Pompeii on the Icelandic island of Heimaey.

An easy-to-miss garden in Boston's North End honors the mother of JFK and others who lost children in WWII.

27-room home built with the fortune of a sugar magnate.

The shortest in the world, this landing strip stretches a mere 1,312 feet before steep cliffs on either end plunge into the Caribbean.

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

The ancient past meets the retro-future at these dinosaur tracks that are protected by a geodesic dome.

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

Sniff the Titan Arum's rotting flesh.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.