Sunyshore City is located at the extreme east of the map of Sinnoh. The city's roads and streets are made of solar panels, because the city uses too much electricity and would have had little land to walk on. The solar panels are made into a walkway, where you need to walk on it in order to reach to the Gym. There is a lighthouse in this city. To the north, is the Pokémon League. Sunyshore City has the Sunyshore Market where it sells Seals. It sells different types of Seals everyday. It's speculated that Sunyshore City is the hometown of Cyrus, leader of Team Galactic.
The Sunyshore Gym is the eighth Gym in Sinnoh. The whole gym is made of massive gears, and there are switches on some gears which can turn the gears. Different colors of the switches rotate the gears a different amount of times and in a different direction. Green colored switches make the gears rotate once in an anti-clockwise direction. Blue colored switches make the gears rotate once in a clockwise direction. Red colored switches make the gears rotate twice in a clockwise direction. There is however one trainer in the gym disguised as a Pikachu.