The crossing nearest Yuma, AZ, is San Luis. But going west on Hwy 8 from Yuma, you can reach Los Algondones in Mexico, the other side of the border with California. San Luis sees a flood of Mexican nationals cross into Arizona where a hundred thousand acres of vegetables grows year around, farmed by 25 thousand living in Arizona and another 25 thousand that come across the border to help with the work, almost on a daily basis. When the high heat of summer rolls around, they will grow cotton.
Lots of store front busineses offer the usual dental, eyeglass, medical and pharmacy items at a much discounted price, that comes with very fast service. Kiosks have a lot that comes north from the Mexican hinterland, with a few Chinese items included, as well. Get a haircut, a good lunch, and a have good time when some music starts up.