D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

A super-sized promotional trick that is now a D.C. landmark.

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

Largest Roman Catholic church in North America.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

A nostalgic bibliographic gem.

The walls of the iconic dome are hollow and have a secret stairway.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A historic neighborhood church is reborn as a psychedelic arts collective.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

Home to items never before seen by the public.

An ice cream parlor chain that caters to vegans and pinball fans equally.

A museum dedicated to the history and exploration of both popular music and science fiction.

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

A calm and comfortable place to hang out with cats and kittens up for adoption.

The oldest family-run restaurant in the United States is a living museum of New Orleans dining history.

The world-record holder for the longest bridge stretching continuously over water.

This float factory takes the mask off of Mardi Gras and lets visitors see where the magic happens.

The restaurant keeps a hidden séance room on the second floor and reserves a table for the spirit of the former owner each night.

The second oldest continuously operating bar in Louisiana.