This campground is really great, the main downside is that in order to pay the fee you have to drive to City Hall which is about 2 miles away.
There are both group campsites and individual campsites here. From the entrance road, once you see the camping rules sign you will take a right down a dirt road to the individual sites. Otherwise if you keep driving straight past the portage, then you will find the group sites.
When we arrived there was no one else occupying campsites, so you might have the whole place to yourself!
Things to do around the park:
Hiking trails to Wolf Creek Falls
Boating and fishing
Read about the history of this former sandstone quarry site (there's a collection of interesting info boards near the portage)
Rock climbing including the state's best 12a/b!!! Sigma lives up to the hype. More info on the rock climbing in this area: https://www.mountainproject.com/area/105812719/robinson-park
Ice climbing in winter months (but you'd be crazy to camp in MN winters, in my opinion)
Paddle past the Robinson Ice Cave known to be a popular bat habitat
whitewater rapid rafting