Ocean City MD is a barrier spit ( island ) and is very close to the Assateague Island National Seashore. Vacationers to the Ocean City MD and Delaware Coastal Seashore Resorts can easily drive to the National Seashore for a 1/2 or full day of family enjoyment! CLICK HERE FOR GOOGLE MAP. The web site of The US National Park Service provides a wealth of information about the Island and tips on planning a visit to the Island. Make sure you stop in at the Visitor Center located just before the Verranzano Bridge before you cross over from the mainland to the Island to gather informative brochures, maps and allow the children to explore this small educational and information center. You will find public restrooms here also. Assateague Island National Seashore offers a variety of kids programs during the summer months. Check at the Barrier Island visitor centers for program descriptions and schedules.
I recently took 2 visiting International visitors for a 2 some hour adventure on the Island. We spotted wild deer, and of course the famous Assateague Ponies. 
A 1/2 mile walk along the marsh trail provided a great view of the bay and the ecosystem populated with crabs, birds, marshy grasses and more! Informative displays along the walk provided information about our environment and the wildlife. We also crossed over to the Atlantic Ocean side of the Island and enjoyed the cool ocean breezes and views of the dunes. 
Elena and Guzel found the trip totally refreshing and a great respite from the visiting vacationer populations in Ocean City MD. You will find other informational resources AT THE BEACH about Ocean City MD and the Assateague Island National Seashore. When you are vacationing for a week or even a weekend stay, I encourage everyone to visit this environmental wonder. When entering the National Seashore entrance, the fee is $10 for one vehicle, valid for 7 days. Be sure to bring a spray can of mosquito repellant if you plan on enjoying one of the 1//2 mile walking trails, sunglasses, sun hats, some beverages in a cooler and even a picnic lunch as you will find picnic tables awaiting you at various locations throughout the seashore park. OH! 
You might even want to bring your bathing suits and spend the day on the Assateague beach! There are public restrooms to change clothing in and outdoor showers to wash the sand from your sun drenched body when you return to your car. Bring your camera to capture the moments and the scenery!
Click here to view a few photos taken on Assateague Island during our visit.
This is a great piece on Assateague Island. Thanks for including it. I am new to blogging but was searching Google for Ocean City blogs and found yours. I am particularly interested in information on Assateague because many of my clients who are looking for new condos in Ocean City and who are interested in our bayfront project, The Makai [http://www.makaicondos.com], are looking for information on Assateague. I included some information on Assateague in my blog if you want to check it out on the Makai site.