Mason Neck Tent Shelter (small). The shelter is a 40 x 20 foot framed tent; there are no holes in the center, and sides are open. The floor is gravel. The tent's roof is vinyl. There are 10 picnic tables and two pedestal charcoal grills. It seats 50 people at one time; a group of more than 50 but fewer than 100 people can use the site (although shelter rental does not guarantee sole usage of the area open to the general public). Guests will need to bring lawn chairs. Erecting additional tents is not permitted. Additional tables and grills, likewise, is discouraged. Parking space is adequate, but it may be necessary on busy weekends to offload supplies and park elsewhere in the park, still within walking distance. The shelter is near a general picnicking area that the general public uses. Restrooms are about 60 feet away. There are no electric outlets or water hydrants. Visitors should contact the park to pre-pay parking fees for their group as a whole. The use of a caterer requires a special use permit, which can take up to 30 days to receive. The park is open daily 8 a.m. to sunset; there's no swimming at this park. Each shelter guest must pay applicable daily parking or admission fees. If you'd rather arrange to have such fees for your guests paid up-front, please contact park staff before the day of your event. Also, a special use permit and additional fees may be required for any activities other than simply picnicking; call the park beforehand to discuss such issues. No refund within 14 days before reserved date. Before then, there's a cancellation fee.