HopHopHop Town is an anime-exclusive town in Kanto, more specifically located on the outskirts of Celadon City. The "town" resembles more of a city than a town with its many skyscrapers and buildings. The only trace of any nature in the town is on a skyscraper, where a Drowzee and a Hypno reside. Somewhere in the city is the Pokémon Lover's Club, whose members all suffered from insomnia and used their Hypno to allow them to sleep more easily with Hypnosis, though that move caused detrimental effects to HopHopHop Town as a whole. Additionally, HopHopHop Town is the location where Psyduck was captured by Misty.
HopHopHop Town was visited by Ash & Co. in the anime just after battling Erika, where they learned that several children had disappeared and that several Pokémon were suffering from excessive fatigue despite their relaxed activities. An investigation with Officer Jenny revealed that the Pokémon Lover's Club had been using a Hypno to help them fall asleep, which's Hypnosis move's waves radiated to cover all of the town, affecting all of its inhabitants. However, in the attempt to capture Hypno, Misty was hypnotized and ran into a park thinking that she was a Seel, where she found the missing children, who also thought themselves to be varied species of Pokémon. With the help of a Drowzee that also resided in the park, Misty and the children were healed and HopHopHop Town was relieved of the problem.
The garden at the top of a building looks very familiar to another place in another episode.