The Capital Crescent Trail was built upon the abandoned railbed of the 11 mile Georgetown Branch of teh B&O Railroad. Technically, the trail goes as far north as Silver Spring but I always start off on Bethesda Ave. in downtown Bethesda.
The Trail is almost all completely hard surfaced so it is super easy for novice bikers to travel all the way to Georgetown. (Please note that when my husband and I first started dating, I took him biking on this trail for a leisurely ride. Little did I know that he was super out of shape and confessed that he almost dumped me because he was about to pass out!) Although the weekends can get a bit crowded by road bikers, it is very stroller friendly and a great stroll for the kids!