A castle built by an eccentric medieval enthusiast in suburban Ohio.

The oldest surviving botanic garden in the United States.

The monumental steeple on Amherst College's campus has no church attached to it.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A giant Troll lurks under one of Seattle's oldest bridges.

A layered tribute to the work of mosaicist Isaiah Zagar.

Elevated freight railway turned wildly successful urban park.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

This replica of the Greek structure is in the heart of Nashville.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

Elvis's own personal tropical hideaway.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

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

An alley covered with 20 years of bubble gum.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Two massive rock outcroppings on the Oregon coastline.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

Erotic art covers the walls of the largest ancient pleasure palace.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

An exquisite collection of fairytale conveyances that puts most car museums to shame.