This famous fort (famous for Purandar treaty) is located on Narayanpur - Saswad road. Narayanpur is about 40km from Pune on Pune- Satara road
About:
Purandar fort (also called Purandhar fort) पुरंदर किल्ला (in Marathi) figures repeatedly in the rising of Shivaji against the Bijapur kingdom and the Mughals. Purandhar fort stands 4,472 ft. above the sea (1,387 m) in the Western Ghats, 20 miles southeast of Pune. It actually consists of two forts - Purandar and Vajragad (or Rudramal). The latter is the smaller of the two and is on the eastern side of the main fort.
In 1596, when Bahudar Shah of Ahmednagar sultanate granted Maloji Bhosale(grandfather of Shivaji) Poona and Supa, the fort of Purandar was included as well. In 1646, a 19-year-old Shivaji in one of the first victories of his legendary career, established control in the fort. In 1665, it was besieged by the forces of Aurangzeb, under the command of Mirja Raja Jai Singh, a Rajput general, assisted by Diler Khan, an Afghan. The defense of Purandar by Murarbaji Deshpande of Mhar, the killedar (keeper of the fort) was obstinate and he lost his life in the struggle to retain the fort. Raja Shivaji daunted at the prospect of the fall of his grandfathers fort, signed a treaty (the first Treaty of Purandar) with Aurangzeb. Purandar fort along with Vajragad, Sinhgad and 22 other forts came under the Aurangzeb's control and Shivaji Raje became his jahagirdar (glorified tenant). This truce did not last long as Shivaji revolted against Aurangzeb and recaptured Purandar only five years later in 1670. Thereafter, Shivaji spent prolonged periods of time here. Sambhaji raje, Shivaji Maharaj's eldest son and successor was born at Purandar fort.