Camping in Henlopen State Park was a great idea! My group was there, on two adjacent sites, from Sunday to Tuesday, in early June. The weather could not have been more ideal! We were on sites G12 and G13, which were both really large. Here's the rundown:

Pros:

• Clean, accessible bathhouses

• Really large tent sites

• So close to the beach and nearby Rehoboth and Lewes (great dining and shopping)

• Easy-burning firewood

• Access to a camp store

• A pretty quiet campground altogether

• Campground fee includes beach access so you don't have to pay again

Cons:

• It's busy! Be prepared to wait to get into the park for 15-45 mins due to traffic backups at the entrance gate

• The walk to the beach is a LONG one

Neutral Thoughts: 

• The campsite as a whole is a very busy one--there's a lot going on from bike riding to frisbee throwing