The name of the town, written either way, is "Sorashiro". The original spelling of the town name, 空白 (notice it's not 口), also means "blank space" and is pronounced "kuuhaku", but when it's written as the name of the town it's "Sorashiro".
@firelordzuzu the aquarium the old couple went to when they were young was just some random non-deep sea one with a venus' flower basket exhibit.
as stated in chapter 1, MagMell opened 5 years ago as the first deep sea aquarium