According to local lore, this narrow passageway through two large rocks was accidentally created by the devil himself.

These eerie outliers of the lightning bug family glow a mysterious blue color.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A working cattle ranch with remarkably well-preserved prehistoric petroglyphs and ancient ruins.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

One of the American Southwest's most extensive collections of Navajo rock art.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

In Portugal, a secluded stretch of untouched natural beauty hides at the bottom of a steep hill.

Iron Age runes and ruins hide in plain sight along this Portuguese beach.

One of the few places in Portugal where the Celtic ritual of wearing large wooden masks is still practiced.

An ancient tomb that still stands in Portugal.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

Dead weights honor the dead of Portugal's fishing industry.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

An early work of the architect Álvaro Siza Vieira, these swimming pools blend into the beach.

One of the largest Roman settlements in Portugal.

Ancient catacombs form the foundation for this Rococo orgy of a church.

This crumbling Portuguese ruin overlooks the populace it once ruled.

This abandoned five-star hotel is now a five-star urban exploration destination.

A garden in Lisbon filled with giant porcelain creatures.

A small Portuguese cottage formed between boulders in the countryside.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.