A well-preserved example of an early industrial operation in the northeastern United States.

What looks like a simple quaint estate in rural Pennsylvania was in the 18th century home to a small monastic community.

A tradition unlike any other, this marks the site of the annual Groundhog's Day tradition.

These lush botanical gardens employ the most purrfect pest control force.

A daily replay of the experiment that proved the rotation of the Earth.

A local prank turned town icon.

Yo, Adrian!

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

Mysterious rocks that ring musically when struck.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

The final residence of an educator, civil rights leader, and presidential advisor was also the first headquarters of the National Council of Negro Women.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

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

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

A haunting tribute to pioneering photographer Clover Adams.

A super-sized promotional trick that is now a D.C. landmark.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

This historic rec center in the heart of Israel is a bastion of peace and togetherness.

Built by a king and rebuilt by an emperor, this aqueduct transported water for 1,200 years to this ancient Mediterranean hub.

This archaeological site was the center of the extinct Yarmukian culture which developed the first roads and pottery in Israel.

Dozens of elegant ceramic tiles decorate these ancient walls, each displaying the Lord's Prayer in a different language.