Options for staying in eco-friendly or sustainable accommodations:

1. Eco-lodges: These are accommodations designed and operated with a focus on environmental sustainability. They often use renewable energy sources, conserve water, recycle waste, and integrate themselves into the natural surroundings. Examples include Hamadryade Lodge in Ecuador and the Alila Villas in Bali.

2. Green hotels: These are traditional hotels that have implemented environmentally-friendly practices. They might use energy-efficient lighting, minimize water usage, and provide recycling facilities. Examples include the Bardessono Hotel in California and the Proximity Hotel in North Carolina.

3. Eco-resorts: These are larger-scale properties that incorporate sustainability practices into their operations. They may have conservation programs, organic gardens, and employ local staff. Examples include Soneva Fushi in the Maldives and Lapa Rios Ecolodge in Costa Rica.

4. Farmstays: These accommodations offer the opportunity to stay on a working farm or ranch. They often promote organic farming practices and offer farm-to-table dining experiences. Examples include Glynwood in New York and The Farm at San Benito in the Philippines.

5. Glamping sites: Glamping combines the idea of glamorous accommodations with being close to nature. These sites provide luxurious tents or cabins with minimal environmental impact. They may use solar power, composting toilets, and eco-friendly products. Examples include El Capitan Canyon in California and Clayoquot Wilderness Resort in Canada.

6. Home rentals: Many homeowners and hosts now promote eco-friendly practices in their properties. You can find homes listed on platforms like Airbnb that have energy-efficient appliances, recycling facilities, and the use of eco-friendly cleaning products.

7. Hostels and guesthouses: Some budget accommodations aim to be eco-friendly by implementing water and energy-saving measures, using natural materials, and promoting responsible tourism. Examples include Elements Hostel in Thailand and Solheimar Eco-Village Guesthouses in Iceland.

8. Treehouses or eco-cabins: These unique accommodations allow guests to stay in elevated structures built around trees or in small off-grid cabins. They often blend into the natural environment and use sustainable materials. Examples include Treehotel in Sweden and Madre de Luna in Spain.

9. Retreat centers: These centers provide a peaceful environment for guests to relax and rejuvenate. They often emphasize eco-friendly practices, mindfulness, and reconnecting with nature. Examples include Esalen Institute in California and Suryalila Retreat Centre in Spain.

10. Houseboats: Staying on a houseboat can be a sustainable option as it minimizes land usage and can use solar power for electricity. Examples include Houseboat Hotels in the United Kingdom and Backwaters in India.