That's a good idea. Game Freak has tried to do that-ish. Ex. Eterna City has Eterna Forest before it hinting the coming of a grass-type leader. It always amazed me that a forest could fit in a Gym. Also Castelia Gym got me so confused. I mean really, honey coated walls and a nature theme in aEven though this is very unlikely to occur in the 5th generation(only because of the map) i would love to see the gyms added with thier respective enviroments instead of in a building in the middle of the city
Ex Fire- gym inside a volcano
Electric- Gym is a power plant
Poisen-( in the future) maybe in a hospitol and the gym leader is a doctor