In the morning, head to Rajmachi Fort located between Mumbai and Pune. It's a moderate trek that takes around 2 hours to reach the top. You'll get an amazing view of the Sahyadri mountains and the surrounding valleys. After lunch, visit the Kondhane Caves, an ancient Buddhist cave complex. Finish the day at the Karla Caves, another Buddhist rock-cut cave complex located near Lonavala.
Start the day early and head to Tarkarli Beach, one of the best places for scuba diving in Maharashtra. You can see a variety of marine life including corals, fish and dolphins. After lunch, visit the Sindhudurg Fort, a historic sea fort and explore the tranquil Malvan town. Relax on the beach and enjoy the sunset before heading back to your hotel.
For the final day, head to Kamshet, a popular destination for paragliding in Maharashtra. You can enjoy the bird's eye view of the scenic Western Ghats while experiencing the thrill of paragliding. After lunch, visit the Bhaja Caves, one of the oldest Buddhist cave temples in India. If you have time, stop by the Lohagad Fort, a hill fort with scenic views of the surrounding landscape.
Other adventure activities that you can consider are river rafting in Kolad, rock climbing at Naneghat and rappelling at Dukes Nose. A side trip to the hill station of Mahabaleshwar can also be a great addition to your itinerary. To maximize your fun, try to start your day early to avoid the heat and crowds. Don't forget to carry sunscreen, hats, and comfortable shoes for the treks.