This residential door allows San Francisco muggles a glimpse at the wizarding world.

A free, public museum dedicated to the fascinating science of sight.

A measuring mishap led to these artificial stone ladies losing their stomachs.

A memorial for public executions that dates back to the 14th century.

From the sky, a kaleidoscope of color brightens the grey landscape of the San Francisco Bay.

A gathering of green robots at the Googleplex.

It took years to decode its mysterious messages.

A quiet, semi-secret square with statues of Mahatma Gandhi, Virginia Woolf, and a conscientious objectors stone.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

An abandoned concrete jungle surrounded by a lush park.

The world's first permanently occupied mountain-top observatory continues to report on the stars.

A burnt orange monolithic dome structure perched on a hillside near Interstate 280.

Frank Lloyd Wright died a year before construction on his largest public project even began.

340 bicycles, 65 feet high.

A huge work of Burning Man-inspired outsider art on the grounds of a California winery.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

Two mammoth statues inspired by equally tall tales lure tourists to this roadside attraction.

A collection of colorful dinosaurs hidden in an actual rainforest.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

Speak to a companion on the other side of the room loud and clear through this architectural anomaly.

The life of one of America's pre-eminent painters is frozen in time in the home where he lived, worked, and died.

A city park that sits on top of a freeway.

This downtown Dallas art installation is always on the lookout.

According to legend, this rock represents a young girl trapped by an evil ocean spirit.