The "best" group can vary based on individual preferences, trek difficulty, and other factors. Here are a few popular trekking groups in Mumbai: Mumbai Trekizens: Mumbai Trekizens is a well-known trekking group that organizes one-day treks and outdoor activities in and around Mumbai. They offer a range of options, including treks to nearby hills like Kothaligad, Rajmachi, and Karnala Fort. Trekking Trails: Trekking Trails is another reputable group that conducts one-day treks from Mumbai. They organize treks to destinations like Matheran, Lohagad Fort, and Sudhagad Fort, among others. Mumbai Travellers: Mumbai Travellers is a travel and adventure group that offers one-day treks and hikes for outdoor enthusiasts. They organize treks to places like Rajmachi, Kalsubai, and Bhimashankar, providing transportation, guides, and a well-structured itinerary. Wild Rangers: Wild Rangers is an adventure and trekking group that conducts one-day treks near Mumbai. They organize treks to places like Kalavantin Durg, Harishchandragad, and Korigad Fort, providing experienced guides and a supportive team.