Maple Drive is a vast and very active street in the city of Danville. Phineas and Ferb normally perform their activities here, seeing the fact that their home is here, and most of their creations are within their backyard area. The only times it doesn't really appear is when Phineas, Ferb, and the gang are doing their project away from their home (ex. London, grandparent's house, downtown Danville, moon/other planet, etc.)
In "Put That Putter Away", it was shown that Doofenshmirtz had a house that was two houses down from the Flynn-Fletcher house. The layout of these houses were never seen in any other episodes, however, and in all other scenes of Maple drive, it was shown that there were only two houses next to the Flynn-Fletcher house before the street ended.