A self-built castle made by a mysterious man.

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

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

A sharp bend in a dramatic river canyon cut through red rocks.

A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.