Ghangad Fort is around 400 years old and it is believed that it was used by the Peshwas to keep the prisoners. From the top of the fort i.e. Balekilla, one can enjoy astonishing views of the Mulshi dam, Korigad Fort, Tailbaila and Siddhagad fort.
The cheapest and the convenient way to reach the Ghangad Fort trek is via railways.
What I will suggest is to hire a bike from Lonavala/Pune/Mumbai (INR 300-400) and explore Ghangad Fort on a road trip as the landscape views all along the routes are spectacular.
Avoid taking the Tamhini Ghat route, after exiting Tamhini Ghat Road the road till Bhamburde is in very bad condition.