Sector 301 was an administrative area of Mega-City One.
Pre-Apocalpyse War Numbering
The devolved remnants of the Ape Gang were exterminated by Judge Dredd in the ruins of Sector 301 in 2104, following the Apocalypse War.
Post-Apocalypse War Number
Sector 301 was an isolated North Sector of Mega-City One whose nickname was 'The Pit'. It had a high crime rate and Sector House 301 was generally regarded as a dumping ground for problem judges.