Andheri is a suburb or 'Taluka' of Mumbai, situated in the west of the city on the Salsette Island. Andheri derives its name from a small hill called 'Udayanagari' located close to Mahakali Caves. Like many other localities in Mumbai, the railway line divides Andheri into two parts – east and west. It is a residential cum commercial area of the city of Mumbai. It has a population of 1,500,000 and is the largest suburb of Mumbai and the third largest Taluka of Mumbai by area. In the mid twentieth century, Andheri was known for its various movie studios, which have since been relocated northwards towards Goregaon Film City. Sher-e-Punjab Housing Society is the single largest co-operative residential housing society in Mumbai with 1,251 members. The Andheri railway station is the among the busiest railway stations in the country and also on the Western Line of the Mumbai Suburban Railway and the expansion of the metro in the Versova-Anderi-Ghatkopar corridor is part of the government's master transportation plan.