World's largest collection of serial killer artwork and other macabre exhibits.

An artsy hidden staircase leads to breathtaking views of San Francisco.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

This series of Scottish caves has no clear purpose other than baffling historians.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

360° views of the city plus five floors of optical illusions and hands-on science.

Swarms of butterflies cannot compare to the awe inspired by the publicly-funded nakedness once displayed in this sunken garden.

A couple turned their front yard into an artistic masterpiece.

It would be a crime to miss it.

This unique sanctuary invites you to interact with the beautiful birds.

These unusual houses look like giant boats that washed ashore on a residential street.

The oldest structure in a beachside California city was built to serve eight students.

This large collection of tiny things revels in the art of fine machinery well made.

The overgrown ruins of a once thriving World War I-era copper mine.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

Huge masonic hall in Philadelphia with lavishly themed rooms.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.