Amid skyscrapers and traffic exists this unique aquatic ecosystem.

The last example of an innovative piece of surveying equipment now stands in its inventor's hometown.

This once prosperous community was home to European settlers and the Ojibwe.

These Great Lakes sea caves accessible by boat in the summer turn into temples of ice reachable by foot in the winter.

A blast of nostalgia awaits visitors to this miniature indoor raceway.

This former tuberculosis research hospital endeavored to cure the dreaded disease with fresh air and positive attitudes.

An attractive alpine lake at 8,400 feet that is accessible via a paved road.

The world's only teal arches exist in a city that cares more about its aesthetic than an Instagram influencer.

The steepest tramway in North America provides stunning views of the out-of-the-way Wallowa Mountains in northeastern Oregon.

A concrete arrow from a 1920s network of airmail beacons is still preserved at the western edge of suburban Reno.

This former water source for the City of Brooklyn is now a thriving natural wetland.

The preserved remains of the former Milwaukee County Hospital for the Insane are hidden in the wooded grounds of County Park.

A bizarre roadside attraction and the first instance of miniature golf in the world.

A small abandoned and abused cemetery that has become a magnet for ghost hunters.

It's not a typo, now say it five times fast!

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

Natural rock water slides hidden in the remote forests of northern Idaho.

Part of a highway network meant to connect Miami to Montreal, this 10-mile stretch of road made from red bricks is still around 100 years later.

This homestead was occupied by Union soldiers, who believed the owners were signaling Confederate forces.

A home built with marble tombstones from the graves of 2,200 Union soldiers buried in a Virginia cemetery.

The farthest you can be in the contiguous U.S. from a McDonald's location.

At this gas station in the middle of the desert, a convenience store has been carved directly into the rock.

From horses to stainless-steel trucks, this iconic Providence burger wagon is one of the oldest mobile diners in the country.

A small brick parlor house and artist's studio located in the wilderness is surrounded by imposing suburban palaces.