The Katraj to Sinhagad (K2S) trek, a challenging 16-kilometer route near Pune, traverses rugged terrain with steep ascents and descents, offering panoramic views of the city and the Sahyadri mountain ranges; popular among trekkers, especially for night hikes culminating in a sunrise view from Sinhagad Fort, it demands good physical endurance and appropriate gear, making it a memorable adventure through nature and history.