This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A blacklight mini-golf fever dream pays tribute to the iconic rock band.

The bullet-riddled wall from the St. Valentine's Day Massacre, bloodstains enhanced for your viewing pleasure.

An overlooked memorial honoring the local Washington residents who died in World War I.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Home to items never before seen by the public.

World's first "penitentiary," meant to be humane, drove men insane.

A faded sign from the 1920s remembers Baltimore's resistance toward banning alcohol.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

Enchanting gardens surround a derelict mansion, all hidden in plain sight behind a stone wall.

If there's another drive-through golf-cart bar in a bat-filled cave on top of a mountain, we don't know about it.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

A scenic fort on the harbor protected Philadelphia from an attack that never came.

A mammoth pair of Civil War artillery guns abandoned out in the forest.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

A preserved factory in the "Home of the Carrousel" is now a museum dedicated to the classic wooden ride.

A bit of retro transportation flair preserved in the world's largest department store.

A popular European tradition makes its way to the states on one of America's most famous bridges.

This giant iron playfully pays tribute to an early 20th-century architectural trend.