The Sword Fighting Arena is where campers go to duel and practice sword play. It is between the cabins and the Armory. There are straw dummies in Greek armor scattered around the room and training swords.
The Climbing Wall is a giant wall which Greek demigod campers climb at Camp Half-Blood. They must climb quickly or it will clash with the other wall, causing lava to pour from the top, and boulders to fall on whoever is climbing at the time.