REOPENS Memorial Day 2023. Sun Outdoors Frontier Town Water Park, located just outside of Ocean City, Maryland, features five thrilling, twisting, turning water slides. Spiral down 500 feet of spine-tingling tubes on The Rattler. Speed down the Tube Slide. Float away on the Lazy River or relax in a cabana with a drink or snack from the Poolside Bar & Grill. Free to registered guests.