19th century tunnels burrowed under Liverpool.

This pedestrian walkway cuts through a cemetery and over several burial vaults.

A harem-inspired Moorish fantasy design in a Victorian-era Welsh castle.

A complicated contraption for telling time by the moon.

An extraordinary library and archive dedicated to the history of the Arctic and Antarctic poles.

A treasure trove of astronomical, mathematical, and scientific instruments at Cambridge University.

Numberless clock creates a meal of time for the dreaded, insectile Chronophage.

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

The fantastic charm of England's oldest botanical garden has made it a place of writerly inspiration for centuries.

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

Niagara Falls holds a special place in Nikola Tesla's history, so they put a statue on it.

A memorial to the tens of thousands of Irish who fled to North America during the Great Famine.

One of the foremost Sherlock Holmes collections is hidden away at a Toronto library.

This Toronto garden collects stares and tchotchkes in equal measure.

Lost subway station nestled beneath Toronto's busy commuter line.

A collection of human remains, animal body parts, and other macabre curiosities all legally for sale.

The Victorian-era greenhouse is stuffed with tropical plants, and open 365 days a year.

A book collector's dream, this Toronto bookstore has the world's first "Biblio-Mat," a random book vending machine.

One of Canada's most incredible rare book collections holds hundreds of thousands of gorgeous tomes that the general public can touch.

A botanically themed auditorium blooms within the world’s last operating double-decker theater.

This Japanese-inspired labyrinth of hot springs is hidden in a Chilean forest.

The largest stone moai on Rapa Nui.

This odd Chilean waterfall-cano hotel must be entered via a rope bridge.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.