South of the Maidan and Park Street, Calcutta spreads towards suburbs such as Alipore and Ballygunge, both within easy distance of the centre. The thoroughfare that starts life as Chowringhee proceeds south from Esplanade past Kalighat to Tollygunge , following the Metro line which terminates near the luxurious Tollygunge Club, the mansion of an indigo merchant now surrounded by immaculate golfing fairways and bridle paths. Northeast of Tollygunge, beyond a white-tiled mosque built in 1835 by descendants of Tipu Sultan, the vast open area around the Rabindra Sarobar lakes leads to Ballygunge , the home of Calcutta's Bengali middle classes.