A relic of Victorian grandeur hides beneath a busy South London road.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

One of the figures in this Celtic sculpture continues to puzzle archaeologists.

This Viking gravestone carved in a rare runic style was dug up from a London churchyard.

It's a mystery why these remains were found with no traces of their bodies in sight.

The gigantic skull of a long-extinct species that once roamed the forests of England and Ireland.

This hidden green space is the city's second largest conservatory.

This small collection of rare books was uniquely locked up for safe keeping.

A Victorian natural history and ethnographic museum with wonderful turn-of-the-century, science-book-esque evolution displays.

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

A little slice of Japan and its aesthetics in London's Holland Park.

Behind one of the world's most impenetrable vaults is a massive collection of retail silver.

This inn of the court provides a fascinating window into London’s legal and architectural history.

A cluttered and astounding collection of antiquities and curiosities.

This haunting sculpture was created as a statement on the mechanized warfare of the First World War.

This ancient oak plays host to carvings of magical elves, gnomes, witches, and other creatures prominent in local folklore.

This marine reptile was discovered by one of the 19th century's greatest fossil hunters.

Tombstones and enigmatic inscriptions hide within a vault beneath a popular London arts venue.

This Underground station has been a popular filming location for decades, even before it closed.

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

An abandoned company town and cement factory outside of Bogotá, now haunted by ghosts and scofflaws.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

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

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