There are many interesting things to do here, but one activity that is interesting is finding shark teeth. An example of a beach where you can find shark teeth is Brownie Beach in Calvert County. Here, they range from barely a millimeter up to several inches. Other items found include skate and ray teeth, porpoise teeth, and other interesting items. Fossil hunting sites include (http://www.mgs.md.gov/esi...):
Flag Ponds Park (http://www.calvertparks.o...) provides lovely views of the Chesapeake Bay, wide sand beaches, and a fishing pier as well as being an active site for finding shark's teeth.
Calvert Cliffs State Park (http://www.dnr.state.md.u...) has access to the Calvert Cliffs, site of rich fossil beds.
Bayfront Park also known as Brownie Beach-Route 261, Calvert is possibly the richest shark's teeth hunting site in the area.
The National Oyster Shucking Contest is held at the Oyster Festival each year in St. Mary's County Leonardtown Fairgrounds. A fun two day event with 4H, crafts, beer stands, tractor pulling contests, and of course oysters.