The Hardy River is the wild-feeling counterpoint to urban Mexicali, with calm water for kayaking, fishing, birdwatching, and slow outdoor days. It sits well outside the city centre, so it works best if you have a car and want desert, reeds, and water instead of museums and plazas.
Go prepared for heat and distance. The draw here is not polished infrastructure but the chance to get onto quiet water and see the Colorado River delta landscape at a much gentler pace.