The rogue roots are gradually consuming some of the historic marble grave markers.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

The hidden offices underneath Memorial Bridge have been locked up since 1976.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

The naval commander’s proudest moment in battle is memorialized in this unique tomb at Arlington Cemetery.

Born a slave on the Arlington estate, Parks dug the first graves at Arlington National Cemetery, and was buried there, too.

This oceanside Reykjavik spot is speckled with recycled sculptures and large stones.

Years of archaeology, just chillin' by the water cooler.

To find the "unicorns of the deep" you've got to go downstairs.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

This historic hotel invented the chocolate brownie.

The last masonry skyscraper ever built reveals a transitional moment in architectural history.

An outdoor urban gallery of large-scale artworks by the world's most influential street artists.

In one Chicago park, a trio of werewolves are waiting to devour their fallen brethren.

A goddess-topped water fountain in Chicago was created thanks to the dreams of a thirsty newsboy.

This awkward aquarium sculpture is one of the strangest statues in Chicago.

This tiny museum's sizable collection is jammed into a former underground public toilet.

An encyclopedic collection of mammal penises.

A historic beacon built in the aftermath of the worst maritime disaster on the Great Lakes.

Roses and other fascinating flora fill this garden built to commemorate Britain's immortal Bard.

This monument to one of the largest science fiction games of all time bears the names of hundreds of thousands of players.

This aromatherapy shop and mini-museum cofounded by the Sigur Rós frontman documents Icelandic history through scents.