Rock Creek Horse Center
If you have found that visiting the city was a mistake, and wish you had opted for a country vacation instead, it's not too hard to make believe in Rock Creek Park. The horse center offers trail rides, horseback riding lessons group and private, and pony rides throughout the summer months. The trail rides are very popular, and reservations often run out more than a month in advance. The pony rides and lessons also require RSVP, but are much easier to get. For those visiting on a whim, and not interested in paying these large sums, you can just stop by and pet and feed the horses for free. If you traveled to the city on horseback, they offer full-service public stables for $600/month.
Turtle Park
Turtle Park has the coolest playground in town. The centerpiece is an enormous sandbox littered with eminently climbable turtle sculptures and plastic shovels and buckets. In the summer, you can get the sand off your kids away without a trip to the bathrooms at the "sprayground." The park is fenced in and has plenty of shade, as well as four baseball fields, two basketball courts, two tennis courts, and a rec center.
Uptown Theatre
This movie theater is a historic landmark, hosting many premieres throughout its history. With few exceptions, it shows epic franchise films that can make good use of its large screen 70 ft long by 40 ft wide and great number of seats. If there is a film playing there that appeals to you, it's worth the trip.