Sustainability is a hip buzzword in travel these days, which means, of course, that the term is overused and nobody knows what it really means anymore. Reusing hotel towels and ditching plastic straws are small steps in the right direction, but there’s strong evidence that travelers are eager to go much, much further. In fact, more than 4.5 million people searched Airbnb for eco-friendly listings and bookings last year alone. Travelers who truly want to “leave no trace” on their next vacation might focus their search on Taos, New Mexico. Rising from the ground in the Sangre de Cristo Mountains, more than a hundred homes known as Earthships offer the ultimate in sustainable living – and more than a dozen of them are available to rent on Airbnb. From the outside, an Earthship might be mistaken for an otherworldly dwelling – part Pueblo, part space capsule. But step inside and you’ll find, well, normality. There’s high-speed Wi-Fi and flat-screen TVs. Kitchens equipped with refrigerators and ovens. Modern plumbing and washing machines. So, what makes these Earthships self-sufficient? For one, these homes are off the grid and generate power from solar energy. Plus, sewage is contained and treated on site, and the walls are constructed using old items such as tires, cans, and bottles that have been thrown away. And for those of you who want to do a ‘sustainable’ trip but don’t feel like going to New Mexico, no worries: you can find Earthships all over the world and in all 50 states.