This Hindu temple is an architectural marvel designed and built according to ancient Indian principles.

A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

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

In this century-old literary safehouse, print is alive and well.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

Rome's ancient Etruscan rival, now a park full of ruins.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

Sniff the Titan Arum's rotting flesh.

Ride the subways of yesteryear.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

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.

It's clear this abandoned Art Deco gem was no ordinary cleaners.

Murals made with millions of colorful stones adorn the abandoned building.

The underground mall's skylights look like they could be part of a spaceship.

This incredible college library is a visual masterpiece of mosaic art. It also looks kind of like a giant boombox.

A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

This traditional garden in the San Fernando Valley doubled for Star Fleet Academy, and is irrigated entirely by wastewater.

In a city filled with Frank Gehry buildings, one stands out as one of the architect's weirder works.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.