A modern temple with an ancient philosophy.

At the right time of day, sunlight floods through the roof of this cave and illuminates the small pavilion hidden within.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

The sanctuary seems to either float atop the water or sink into the dirt, depending on the water level.

An elegant space dedicated to a master of romanticism and minimalism.

One of the few places in the world where visitors can walk alongside fossilized tracks from 80 different dinosaur species.

A careful eye can find hundreds of dinosaur tracks running along the Connecticut River.

When an ancient supervolcano erupted, some of Nebraska's prehistoric animals were forever preserved in ash.

What happened to the three lighthouse keepers who vanished from this place remains a mystery over a century later.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

The "Bridge Over the Atlantic" lets you cross the waterway in mere seconds.

An emerald-green grotto just a short trip from Austin.

This abandoned church in central Lyon is missing its front stairs.

The city walls of Salé lead to the ruins of this seaside "bastion of tears."

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

The 1940s structure houses what was once Europe's largest telescope.

This old medieval prison tower has been a site of astronomical research for more than 250 years.

Despite having a dome made of papier-mâché this tiny observatory has survived for over a century.

Finland's oldest astronomical observatory once played a crucial role in seafaring and timekeeping.

This ancient Chinese observatory still contains early astronomy technology.

This observatory within Europe's first dark sky park offers stunning views of the night sky.

A world-class observatory in the California desert.

This humble star-gazing center touts itself as the "Birthplace of American Astronomy."