Originally Posted by
brendog
If you at all athletic, I highly recommend renting a bike (Not one of the crappy red bikes...) and riding the C&O Towpath out for a ways. It's fairly flat and graveled, and provides some great views of the Potomac, particularly if you take the easy 20ish mile ride out to the falls. Cycling around the Mall at night is also quite scenic, and there are fewer tourists wandering about.
DC is a surprisingly good biking city, despite the crap drivers and utter lack of parking.
i thought the W&OD trail was paved, and ran all the way from the potomac to purcelleville, including bridges over i66 and i95.
the mt vernon trail runs beside the potomac from dc (va) to mt vernon. the trail does go through streets in alexandria(i think). there is a spur over the wilson bridge with great views of dc . do not continue into ft washington. there is no bike trail.
these guys maintain a list:
http://bikewashington.org/trails/index.htm