A "house to which to flee" for settlers in colonial Pennsylvania.

The famous bell was secreted away and hidden in a church in Allentown during the British occupation of Philadelphia.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

A winding, cliffside stretch of road overlooking the Delaware River.

This huge, disused viaduct is now a crumbling concrete underworld of covered in years of graffiti.

Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.

The remains of a community that was forced to move for a dam that never materialized still rot in this Pennsylvania park.

The meteor that sealed the fate of the dinosaurs landed at this site, one of the largest impact craters in the world.

One of the few places where you can visit a cenote and Maya ruins at the same time.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

It would take you approximately an hour and a half to walk to the end of Mexico's largest pier.

Iconic red and white plaques show the creative names invented to navigate the city streets.

These mosaic designs promise a cure for headaches, toothaches, and colds.

A hacienda that features all things uniquely Yucatán.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

Every equinox this Maya pyramid puts on a spooky ancient light show.

These winged Maya figures are the subject of speculation and conspiracies.

This small, yet notable, cable-stayed bridge was built to support tourism to a series of internet-famous pink lakes.

At least seven hues of blue and turquoise make this freshwater lagoon unique.

This city's cultural center is in a restored Spanish colonial home from the 1800s.

A bright, colorful telling of the history of Mexico's youngest state.

One of Mexico's least-visited archaeological sites is tucked away inside a theme park.

This heritage rail line meanders through Delaware’s Red Clay Valley.