The plants form a living library and laboratory for researchers and students at Michigan State University.

The deadly but beautiful ornamental oleander was planted all over the island of Galveston after the hurricane of 1900.

The largest historic preservation organization in the United States.

This well-traveled chess park offers scenic views of the pacific and a colorful, eclectic clientele.

This sprawling farm was once a Cold War-era hideaway for the nation's top diplomats.

A statue honoring 44 continuous years of greeting passing ships.

There's an old indoor swimming pool hidden directly underneath the White House Press Briefing Room.

Once a thriving business district, this former shopping area is now an urban ghost town in the heart of the city.

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

A massive volcanic plug is now a protected area that hosts a number of bird species.

Downtown Minneapolis mixed art and function by turning some of their sewer covers into works of art.

This bridge uses an inverted bowstring truss and is believed to be the only of its kind in the United States.

When it comes to handsignals (and colonialism) rock always beats scissors.

Scenic mount trashmore, Virginia Beach's most curious waterfront still has a couple of secrets.

This seaworthy collection was sparked by one man's passion for sailing.

Although now a decaying ruin, this stone cabin's history includes several notable figures.

This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.

Featuring one of the most complete and original collections of Presidential memorabilia, this is the site of the last front porch presidential campaigns.

Before Nixon, "watergate" meant canals.

At this deceptively beautiful beach, nothing is what it seems.

The sea once considered an ecological wasteland is now called "crown jewel of avian biodiversity" by scientists.

Suburban observatory was personal lab of the father of modern astrophysics.

The artwork that Italians felt California didn't deserve.