From Bulbapedia, the community-driven Pokémon encyclopedia.
Sunyshore Tower (Japanese: ナギサタワー Nagisa Tower) is an anime-exclusive building located in Sunyshore City. The Tower provides the required energy for the various technological machines in Sunyshore City. In Flint Sparks the Fire!, Ash and friends, along with Flint, find Volkner inside the tower. Ash asks Volkner to a Gym battle, but is refused.
In The Fleeing Tower of Sunyshore!, Team Rocket steal the tower and turn it into a rocket ship in order to take it to Team Rocket Headquarters. However they were defeated by Ash and his newly evolved Torterra. Volkner returns the tower to its original place but since it was heavily damaged, he put off the Gym battle with Ash to repair it.
Team Rocket once again tries to infiltrate the Tower in The Eighth Wonder of the Sinnoh World! but Volkner had improved the security in the Tower which made it impossible to take control as they did before. However they do manage to short-circuit the power supply to the Sunyshore Gym shutting out the power while Ash and Volkner have their Gym Battle.
- The Sunyshore Tower is similar to the Vista Lighthouse. Volkner can be found in the Vista Lighthouse in the games, refusing to accept Gym opponents, as in this episode of the anime.
- The Sunyshore Tower resembles the "Tower of the Sun", the symbol of Expo '70 held in Osaka, Japan.