These ruins are a hidden gem, complete with fantastic views over the cliff edge.

Standing atop 2nd-century Roman ruins, this church is one of the oldest and most iconic in Old Cairo.

Naturally protected city carved from a rock face.

This ancient abandoned church in a remote part of Turkey is in danger of falling over.

This ancient city - home to nine civilizations - is soon to be buried under 200 feet of water.

Carvings in Turkey's Marble Road may have directed ancient Romans to a hidden brothel.

Seven early Christians were sealed into a cave where legend has it they slept unharmed for centuries.

The ancient abodes are a testament to human ingenuity amid harsh climates.

This mysterious cliffside carving of an ancient Hittite deity has baffled scholars for centuries.

A section of the long chain that blocked enemy ships from entering Constantinople.

This crumbling medieval basilica once attracted pilgrims by the thousands to collect a miraculous dust that formed above the saint's tomb.

Climb a set of vertiginous stone steps to the top of this impressive ancient edifice.

A Lycian city of the dead carved into the hillside of Southern Turkey, complete with startlingly human touches.

This famous city eluded concrete detection until the early 2000's.

This hunter-gatherer architecture is believed to be the oldest religious complex known.

A deadly ancient portal to the underworld.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

A marvel of Byzantine engineering under the streets of Istanbul.

Roman ruins top white travertine terraces formed by ancient hot springs.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

This giant roadside goose has been hailing travelers into a small Ontario town for over 50 years.

A long-abandoned provincial prison left to crumble in the frigid air of Ontario.

One of Mother Nature’s geological gems, home to many prehistoric fossils.

The ruins of a rehabilitation center for World War II vets can be found in the Westminster Ponds Conservation area.