Talk about sustainable urban planning: A Milan-based architecture firm has proposed a remarkable green development — 100% food and energy self-sufficient — on the 1,375-acre site of a sand quarry in Cancun, Mexico. The outside-the-box, planet-friendly concept would replace plans to build yet another shopping district in the tourist mecca.

Smart Forest City would include housing for 130,000 residents and habitat for 200,000 new trees, which works out to about 2.3 trees per person. And that marks just a small portion of proposed new greenery — a staggering 7.5 million plants of 400 different species. “Thanks to the new public parks and private gardens, thanks to the green roofs and to the green facades, the areas actually occupied will be given back [to] nature through a perfect balance between the amount of green areas and building footprint,” the firm says.

If constructed, the city will be ringed by arrays of solar panels and agricultural fields that can meet energy and food needs, respectively. Community amenities will be sited within walking or bicycling distance of all homes; if needed, vehicle transportation — whether on-road or via boat along a series of canals — would be all-electric, with traditional cars relegated to the outskirts.