Calvert Cliffs State Park is the first place that I visited when I moved to Calvert County and one we always return to with visiting family and friends.
I go here for hikes more than the beach. Though the sandy stretch is picturesque and the water shallow enough for swimming, the portion below the cliffs has been closed since the 2011 hurricane, shortening the available beach to 1/4 mile. Pleasant for a short stay, it can get crowded quickly, so Flag Ponds is better if you want a full day to play in the sand.
Still, for a hike and a picnic, this makes for a perfect outing. Even my 3-year old niece can walk the 1.8 mile trail from the parking lot to the beach without a problem. The path is bumpy in places with tree roots, so you have to be careful, but the terrain is mostly level. We usually bring snacks or a picnic, spend an hour searching for shark teeth and playing in the water, then head back, sometimes diverging to take a longer trail if the weather allows.
To encourage little ones as they get tired, we use the recycled tire playground as incentive to keep moving. (Use this incentive wisely. My niece ran back last time and I had to catch her!) By the parking lot, kids can even climb on a dragon made entirely of tires. There are picnic tables, plenty of grassy areas to run and play, and a few large trees for shade.
The best part of the hikes for us is the nature itself. You’ll see several trees that have been gnawed by beavers and may see a beaver dam as well. The lakes are full of ducks and turtles. We even saw a bright green snake once, but he slithered away quickly.
Entrance is only $5 per car. There are bathrooms near the parking lot and a porta potty near the beach. Bring water, bug spray, sunscreen, and good walking shoes.
http://www.dnr.state.md.us/publiclands/southern/calvertcliffs.asp