One part local history, 99 parts gruesome haunted house.

Hidden beneath the streets of London is a secret subway that only carried mail.

This luxury shopping lane has been protected by its own tiny police force for over a century.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

On a wall in linear London, a plaque hangs at the high water mark of one of the worst floods in fictional Kcymaerxthaereal times.

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

A formerly abandoned mental institute, now back in business.

Unlike other abandoned asylums this empty institution welcomes visitors, just don't go in the buildings.

This mouldering abandoned mental hospital was once a center for progressive healing.

Charleston's historic city jail once held everyone from pirates to Civil War POWs.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

The fairy tale castle of the "fairy-tale king."

A small but immensely extravagant palace built by the "Night King."

Climb the dead electric pylons of Messina.

Norway's national monument to fallen seamen.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

The dome-shaped reservoir of this old water tower produces unique acoustic effects.

A stunning landscape of bunkers that once stored chemical weapons.

Walk through living pictures and music in the Cathedral of Images.

A castle hand-built by a Spanish dreamer in the Australian tropical jungle.

A miniature Italianate fantasy village on the coast of Wales and the set of ITC classic "The Prisoner."

A open air theatre built on a cliff by an eccentric British woman.

Architectureal fantasy quarter of Rome.