A forsaken wonder in the middle of the East Side neighborhood.

This mosque turned crypt is an amazing display of Persian-Islamic architecture.

Tucked inside a South Bank bar is an epic expressionist chronicle of the 20th century.

A gruesome and mysterious ancient sculpture of a pagan deity from the Roman occupation of Celtic Britain.

A marine aquarium with an astounding variety of fish hides in the basement beneath the famous Palm House.

This educational institution and reference library specialize in the psychic arts and mediumship.

This open-air mosaic gallery honoring an English artist took hundreds of volunteers more than seven years to create.

A wonderfully eclectic Victorian aquarium lies in the basement of the Horniman Museum.

A memorial to a dog that inspired rioting in the streets of London.

Explore nearly 400 years of English middle-class home life.

A Roman spa buried deep beneath the City of London.

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.

A closed London rail station created to cart away the dead still bears the marks of attempts to make it less morbid.

Once a train station along the Great Eastern Railway this vibrant coffee shop and bar is where members of London’s creative class mingle.

Wine bottle sculpture with a ship's stateroom inside.

The oldest bibliophilia club in America, with exhibitions on historic books and graphic arts.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

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

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

Chester Cathedral is home to a unique painting crafted on a canvas of cobwebs.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

New York City's smallest piece of private property.

Brooklyn's most iconic restaurant, resurrected.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.