Hearthome City Gym is the official Gym of Hearthome City. In Diamond and Pearl, it was th
e 5th gym. In Platinum, it was changed to the 3rd gym. The trainers here, including the Gym Leader Fantina, use Ghost-type Pokémon. In Diamond and Pearl you had to answer a multiple choice question. Each of the answers is on a door (three for each floor). Go in the wrong door and you battle a trainer. Go in the right door, you advance to the next floor. The questions are basic addition and subtraction problems. In Pokemon Platinum upon entering the Gym you get a flashlight, because the gym interior is dark, save for a maze lined with Duskull masks. If you come across a trainer in the maze you have to battle them. The gym in Platinum is a lot like the Battle Pyramid.