Complex sentence: It was built in the 1960s as a postwar housing estate it is built joining the Gillway estate and cotongreen, but in the 1980s it went down hill, a lot of the maisonettes were housing drug dealers and it wasn't a nice place to live.
Split into simpler sentences: It was built in the 1960s as a postwar housing estate. It is built joining the Gillway estate and cotongreen, but in the 1980s it went down hill, a lot of the maisonettes were housing drug dealers and it wasn't a nice place to live.