Cryptic messages embedded in the New York City sidewalk.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

Mysterious 500-year-old tapestries depict a unicorn hunt.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

New York City's smallest piece of private property.

Elevated freight railway turned wildly successful urban park.

One of Ireland's most infamous prisons for rebels including men, women and children.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

This too-low North Carolina railroad trestle is still a notorious big rig executioner.

This North Carolina store preserves a historic moment in America's movement for racial equality.

Art museum based around the collections accumulated over 58 years by one eccentric thrift store owner.

The highest point in North Carolina and the United States east of the Mississippi River, Mount Mitchell is named after argumentative explorer Elisha Mitchell.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

I-95's Tijuana-style celebration of kitsch at the Carolina border.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

This roadside attraction has been serving out its fair share of hearty folklore and chaos since 1858.

The record holder for the world’s largest peach.

A Nessie-like monster supposedly lurks in this lake.

Formerly the most gerrymandered district in the U.S., it twisted and turned along racial borders.