//
Bladensburg Waterfront Park is just outside the city boundaries to the east, you may be able to take a river tour with a park naturalist. They also rent canoes, kayaks, paddle boats, and rowboats.
© OpenStreetMap contributors
The only aquatic gardens managed by the National Park Service in the country is a marvelous off-the-beaten-path destination in D.C. The Kenilworth marsh is all that remains of the vast marshlands that once covered the riverbanks of the Anacostia (before being dredged for development), and is the only place where you can really imagine the District before it became America's capital. The prime attraction are the cultivated ponds, full of waterlilies, but it's also a worthy destination for the riverfront trail, greenhouses, and birdwatching. The best time to visit is without a doubt on an early summer morning, when the waterlilies are in full bloom. Free summer garden tours are available Sa-Su 9AM & 11AM (Memorial Day-Labor Day).
A very nice non-profit-run public ice rink (the only indoor public ice rink in the city, actually) in Fort Dupont Park. While it's probably not worth the effort to get way out here just for ice skating, if you're in the area, it's fun.
The National Park Service puts on well-attended weekly summer jazz concerts at the Fort Dupont Park Theatre. To get to the stage, turn right on Fort Dupont Dr off of Randle Circle (at the intersection of Massachusetts & Minnesota Aves). Check the events calendar on the website for specifics.
The Honfleur Gallery has one foot in the world of international contemporary art, and one foot in Anacostia. The world inside, with its large, beautiful space stocked with a surround sound system and flat screen TVs, looks like it would be more at home in Manhattan than, well, Anacostia. But it is run by a local nonprofit dedicated to promoting the arts in the world just outside, and in bringing them together with its annual East of the River showcase of local artists' work.
The heart of historic Uniontown is bounded by MLK Jr Ave, Good Hope Dr, 14th St, and W St SE. In this community of well preserved, wooden, Gothic houses, look especially for the colorful Rosie's Row of townhouses on the north side of U St just west of 13th, and for the 1879 St. Teresa of Avila Catholic Church at 1244 V St SE. The neighborhood is small enough where you could easily cover it on foot from the Frederick Douglass House and downtown Anacostia, and you would race through all there is to see in a car.
The Big Chair is Anacostia's most recognized landmark, and it sits right in downtown Anacostia on MLK Jr Ave. It was erected in 1959 as an advertisement for the now closed Curtis Brothers Furniture Store across the street, and at the time of its creation, it was reputed to be the largest chair in the world - 19.5 ft high and .