The Karnala fort trek is the easiest one you can opt for. It begins right at the entrance of the bird sanctuary and leads to an uphill track through thick vegetation. The trail is well laid out and once you have passed the greens, a blaze of orange greets you as does the Fort. From here on, it’s a simple walk, barring a few tricky places. Sit for a while and enjoy the view at hand, before heading back down to a Maharashtrian thali and kokum drink.
Ps: There is also a nature trail, which is a little more challenging