Time of the year to wanders in Sahyadri's i.e when mountains getting greener after 1st monsoon showers.
Place- राजमाची किल्ला,
Elevation- 2700 ft approx
Rajmachi Fort is easy hike in around lonavala. Also trail till base village popular amongst off-road enthusiast for some serious off-roading and mud splashing, though I won't recommend to attempt this stretch to those with lesser experience.
While fort commands stunning view of landscape around and glittery Lonavala town. In present situation there's not much fortification, one can witness few ancient temples, water bodies and caves which are in ruins.
Historical insight- In 1657, Shivaji Maharaj captured the fort and fortified. Later somewhere in late 17th century till early 18th century, it was under Bajirao Peshwa till the time Britishers took over.
Back then, Rajmachi had fort been important trade route between Mumbai and Pune.