Old park right outside the city
Gambrill State Park is great for those just starting out to camp. It is located in Frederick, about an hour outside of Baltimore and Washington D.C. Though the campground is small, each site looks pretty unique. It offers tent sites, electric sites, and 4 cabins. All of the campsites are pet friendly as is Cabin 18. The restroom facility offer hot showers and multiple stalls. One downside is that there is no dishwashing station. You must bring your own dishwashing tubs.
As it is small and located conveniently off of the highway, it is used by a lot of passerbys. This area is very rich in Civil War history so many people will stay at Gambrill as it is a great middle point between Gettysburg and Antietam Battlefields. Right outside the park is the Frederick watershed where many locals take advantage of the trails for mountain biking. The park itself is well known for hiking trails that take you up and around the mountain. Every hiking trail except for the white trail allows mountain biking and horseback riding. Visit in May and the forest will be filled with songbirds. If you are lucky, you may see foxes and bears along with the standard woodland creatures. If you are extremely lucky, you may see the ever elusive bobcat.