Not-so-fearsome tiny trolls live under this wooden train trestle in Portland.

The sole surviving relic of the San Francisco neighborhood cobbled together from old horsecars and streetcars.

This turn of the century masterpiece has a mysterious goaty interloper.

10,000 flowered plants bloom in the City of Roses.

Radioactivity still cause for concern at this urban explorer's paradise.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

A huge musical instrument played by the ocean.

A historic fort commemorating the United States' naval history.

This hands-on math museum believes in turning concepts into constructs.

The art and history of the velvet painting are on full display in this Los Angeles museum.

A 50-foot tile mural mosaic for the 100-year anniversary of the Statue of Liberty.

Tucked in a nondescript downtown Brooklyn mall is a bar containing a remarkable turn of the century anatomical wax collection last seen in 1920s Berlin.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

One part local history, 99 parts gruesome haunted house.

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

Giant, friendly pelicans in Central London, the most unlikely of places.

The television series' iconic giant foot was borrowed from this classical painting.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

London's smallest police station is barely the size of a phone booth.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

An alchemist's "magic door" stands in the middle of a Roman park.