From the Super Mario Wiki
Bonkers Street is a stretch of road located in the city of Victoria, which was seen in The Super Mario Bros. Super Show! episode "The Adventures of Sherlock Mario". The name "Bonkers Street" spoofs that of Baker Street, Sherlock Holmes' home street.
Located in what appears to be the suburbs of Victoria, Bonkers Street has several houses in it, one of which is owned by the famous detective Herlock Solmes. Aside from Herlock Solmes's house, there are little objects in Bonkers Street, aside from some telephone poles and tall buildings. Additionally, the former headquarters of Professor Kooparity was apparently located in the sewers beneath Bonkers Street.