Earthships are sustainable buildings made from natural and recycled materials, designed to be self-sufficient. They utilize passive solar heating, natural ventilation, and rainwater harvesting to minimize reliance on external resources. These structures often feature thick walls made of tires, bottles, and cans, which provide insulation and thermal mass. Earthships can generate their own electricity through solar panels and treat wastewater on-site, making them an eco-friendly option for living in harmony with the environment.