The once-a-day siren is a reminder of the days before time was standardized.

A tribute to the women who quietly kept the local steelworks alive during both world wars.

This tiny business claims to be "the smallest pub on the planet."

Despite its ornamental looks, this towering Tuscan-inspired anomaly was a masterpiece in hydraulic engineering.

An incredibly well-preserved piece of ninth-century Viking poop.

A stained-glass window from the 15th century offers a vision of the end of the world.

One of the shortest streets in York has an especially odd name.

This popular square's history as the former site of a church is right beneath your feet.

Makers and sellers of the original and finest York Ghosts.

Follow the original medieval paths that wind through this intriguing section of the city.

A shrine to one of England's female saints in what is believed to be her former home.

A Reformation-era fiery figurehead once denoted this location as a print shop.

This sculpture marks the spot where one of the greatest Roman rulers was proclaimed emperor.

Semaphore saints, a golden dragon's head, and a stone carved with religious warnings all call this cathedral home.

This commercial and retail center was crafted from walled military barracks.

This futuristic airport terminal was abandoned for decades before reopening as a hotel—with a vintage plane of its own parked out back.

NYC's legendary underground network for bovine transportation.

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

Stone markers on the campus of Gallaudet University commemorate a peculiar school tradition.

The Lincoln Memorial has inspired many, even though a word on the inscription appears to be spelled incorrectly.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.