According to a story that's circulated for centuries, George Washington once threw a silver dollar across the Potomac River. It's unverified, but visitors can check the riverbanks for glints of ancient silver aboard the Capital Wheel at National Harbor. As it rotates, the stately observation wheel lifts riders as high as 180 feet above the river, giving them a birds' eye view of the river's waters and the DC skyline. Conveniently, the observation wheel's seats are enclosed in climate-controlled gondolas, so guests can ride in comfort no matter the season.