Jean Tinguely's bizarre monster sculpture is hidden deep in a forest.

Perfume museum and library.

An enchanting work of outsider art, full of whimsical sculptures and carvings.

The construction of a tram line unveiled hidden remnants of the old medieval city.

The remaining relics of the patroness of Paris lie in a chapel under a striking double spiral staircase.

Museum in a swimming pool where the water still flows.

The world's tallest bridge is also possibly the most elegant.

Hidden away in a modern library are the remains of one of the 18th century's most celebrated wunderkammers.

Science fiction's grandfather has a fittingly marvelous tomb.

A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The vast, legendary catacombs hold secrets much stranger than stacked bones.