The site we had was a pull through that we were able to pull into but were not able to pull out of safely with our 30' travel trailer. They had just finished installing water on every site but we were not charged for the fee for water. The playground was very modern. The kids had a great time riding their bikes. The swimming area didn't look too great and the pond was okay for canoeing with my 10 year old. We probably won't go back but do recommend it. We camped here in a Travel Trailer.
We've stayed here before and will again, since we have relatives nearby, and there are no other options as convenient for us. However, the sites are lovely but primitive. Parking is tight, so larger rigs should avoid. Outstanding locations for tents. We camped here in a Motorhome.
Harold Parker is a treasure close to Boston. The park has miles of hiking, mountain biking and horseback riding trails among eleven ponds for boating and fishing and swimming. There are more geocaches in this park than I have ever seen before. The Rangers keep the bathrooms and showers neat and clean. The sites are large and well spaced. Most sites are surrounded by trees. We come here whenever we need a short getaway. The only issue with Harold Parker is the historic use of the Park as a party place for many young people. The Rangers have started to staple the rule stating "Alcohol is not allowed in any Massachusetts State Park" to every campground map so I believe there will be a zero tolerance for alcohol related disturbances. Even so, inspect your site before allowing the kids to run barefoot. Police patrol through the park and campground regularly day and night. This is a lovely place and the Rangers are doing a great job preserving and restoring it. We camped here in a Travel Trailer.