Catoctin Mountain Park (tel. 301/663-9343; www.nps.gov/cato), a national park, has several good trails and is the home of presidential retreat Camp David -- whose precise location is top secret. The park's entrance is on Route 77 west of Route 15. Admission is free. Tent camping here is $20 a night; cabin rentals are $55 to $140.
Cunningham Falls State Park (tel. 301/271-7574; www.dnr.maryland.gov) has as its centerpiece a 78-foot high waterfall, set in a canopy of 100-year-old oaks and hickories. Stay for a few minutes or the rest of the day. The park is also the site of 43-acre Hunting Creek Lake, which offers swimming, canoe rentals, and picnic areas. Get a guide to the many park trails at the Manor Area visitor center, off Route 15, or at Park Central, on Route 77. Four short trails will take you to the base of Cunningham Falls. Three are in the William Houck Area, off Route 77. They range from moderate to strenuous and from .5 to 2.8 miles. The fourth trail is wheelchair accessible, with a handicapped-only parking lot on Route 77 and a .3-mile boardwalk that goes all the way to the falls. Another trail ends at the Catoctin Iron Furnace, the remains of a Revolutionary War-era iron-making complex. The park is open daily from 8am to sunset. In peak season, fees run $3 to $4 per person; at other times they're $3 to $4 per car. Campsites are available for $25 a night, $30 with electric hookup; cabins are $50.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.