This place is good for what I use it for. I go here with my dogs for short hikes. I have not taken advantage of the full spectrum of what Algonkian Park has to offer. Nor will I ever, since much of it is geared towards children. However for a very local place it works in a pinch with great views of the Potomac River. The downside...it's a well used park. So, you do not go here if you want a secluded experience. And if you have dogs, be very prepared for most park visitors to be visibly afraid of them.
The park offers a waterpark, boat launch, golfing, rental cabins, access to golfing and a small trail system.