Be it EcoTourism, eco-development, or participatory forest management, ecologically sustained activities are of supreme importance to the local communities. This module is an overview of trekking, an EcoTourism activity of the Great Himalayan National Park (GHNP). EcoTourism is nature friendly, sustainable, involves environmental education, and provides an alternative source of income for communities living close to the Park. Visitors coming to GHNP have the rare opportunity to experience the Park's pristine beauty and at the same time help villagers to improve their livelihood options.