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

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

A semi-scholarly approach to sex.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

Hackney's newest private museum and natural curiosity shop.

This innovative steam machine was no doubt the most famous of the pioneer locomotives.

This secret garden has bloomed into London's most unique hub of urban creativity.

An archive of ceramic eggs painted to record clowns' personal makeup designs.

A movable feast that is an East London institution.

The handiwork of a underdog clockmaker who solved an impossible problem for an Empire, and forever revolutionized seafaring.

The anatomical-pathological collection of a man who changed surgery.

This former medical factory gives home to cutting edge arts in the shadow of a gas works.

Residential building on the Regents Canal is a breeding ground for creativity and innovation.

Three small rooms at the back of the “official” church of London's clowns.

The majority of the museum's large collection is held in a storage space open to the public a few times a year.

This museum tucked below a charming cafe gives a brief snapshot of photographic history.

Taxidermied animals galore, by appointment only.

A network of concealed passageways lies within a busy London Underground station.

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

The lab where the scientist made his groundbreaking discoveries is preserved on the basement floor of the Faraday Museum.

A museum wholly devoted to juvenescence.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

The cedar tree in Highgate Cemetery earned its title by accident.