The ground gym can't be found easily, for it is under the bonfire. When the bonfire is moved, you will see a hole. You need to slide down the hole and into the gym. The gym has mud all around it other than a few parts, the standing parts. You fall in the mud, you get stuck. The gym leader and you would each be standing on a special block that balances the battlefield. One wrong move and the field could topple.
