Hiking, biking, sight-seeing, adventure??? (Mumbai)

Hi all,

I have just moved to Mumbai and am looking to explore the city and also to get out and about in the surrounding areas for day-trips and weekends away.

I know a some of this I can do by myself, but also as a way to meet new people and explore interesting and off the beaten track places; are there any good hiking, biking, local adventure / culture groups that you could recommend checking out?

Many thanks,

Kerry