Former villa and estate of James Deering developed to preserve native tropical forests.

A perfect circle of twenty-four mysterious holes dates back to prehistoric time.

These constructed wetlands naturally filter millions of gallons of treated wastewater every day.

The smallest post office in the United States is no bigger than a broom closet.

The longest navigable underground river in the United States is home to countless blind and albino animals.

The first spinning jail built in the United States is the only one that still turns.

If astronomy had a ghost, it would look like this observatory.

The world's largest collection of mechanical puzzles is a cornucopia of analog bafflers.

Display that gathers the basic elements of the universe in one convenient location.

Both funky and traditional, it's the oldest of its kind in Indiana.

Nature and art meet in this curvy creation

This elaborate estate contains a stunning marble aviary, a sunken conservatory, and a magnificent music room with a two-story pipe organ.

A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

A medical facility that has been kept frozen in time.