One of the most rewarding short treks near Lonavala, Lohagad ("Iron Fort") sits on a spur of the Sahyadri at about 1,050 metres, its walls following the natural ridgeline so that the fort seems to grow out of the basalt rock. Originally built far earlier and captured and recaptured by successive powers, it came to prominence under the Maratha king Shivaji in the 17th century, who used it as a treasury stronghold after the 1665 Treaty of Purandar.
The climb from the base village takes about 45 minutes on a stepped path and the views from the ramparts — across the valleys and the surrounding ghats — are excellent in any season, spectacular when the monsoon haze lifts just enough to reveal layers of green ridges. The four gates (Ganesh, Narayan, Hanuman, Maha Darwaja) are well preserved and worth pausing at.
Visapur fort, a larger and slightly more ruined neighbour on the adjacent ridge, is visible from Lohagad and can be done as a longer extension on the same day. The two together make a satisfying full day of trekking. Best in the cooler months (October–February) for trekking comfort; the monsoon path is slippery but atmospherically green.