Gyms are special levels in PTD 1 and 2, just like the real Pokémon games. They have a completely different layout than other levels, and you battle against many Boss Pokémon owned by the Gym Leader. After defeating the Gym, you are awarded a Badge. Gym Leaders are bosses in PTD 1 and 2 and most of them are controlled by a certain Pokémon in PTD 1.

The Gyms in order in PTD 1 are:

40px-Boulder BadgePewter Gym 40px-Cascade BadgeCerulean Gym 40px-Thunder BadgeVermillion Gym 40px-Rainbow BadgeCeladon Gym
Marsh BadgeSaffron Gym Soul BadgeFuchsia Gym Volcano BadgeCinnabar Gym Earth BadgeViridian Gym

The Gym Leaders in PTD 1 respectively are:

Brock SpriteBrock Misty SpriteMisty Lt Surge SpriteLt. Surge Erika SpriteErika
Sabrina SpriteSabrina Janine SpriteJanine Blaine SpriteBlaine Gary SpriteGary

The Gyms in order in PTD 2 are: 

Violet Gym
Azalea Gym
Goldenrod Gym
Ecruteak Gym
Cianwood Gym (Double Battle)
Olivine Gym (Double Battle)
Mahogany Gym
Blackthorn Gym

The Gym Leaders in PTD 2 respectively are:

Falkner, Bugsy, Whitney, Morty, Chuck and Jasmine, Pryce, and Clair

Community content is available under CC-BY-SA unless otherwise noted.