On one of my free days, I spent my time at the nearest but the most overlooked fort in mumbai. Sion Fort. I had been there long back, but not after I started visiting hills regularly. Its close to the station and right on the Eastern Express highway. Exactly at the place where you find the maximum traffic in sion: near the Multiplex Cinema.
I will try and update some historical information if I could find any. Till then, you may want to have a look at the pics.