I journeyed out this evening looking for "my" Mexico. I spent a series of winters in that area of our globe and wondered what there was in SL to remind me of those times. It took a few tries, but I found Chichen Itza, a project of the Mexican tourism board and part of a voting effort for a new Seven Wonders of the World (over with; no results mentioned in the kiosks). It is a veryte impressive building project and while you cannot see me WAY up top the pyramid, I am actually there. And I WAS there in real life some years ago -- in that same spot looking at a slightly different view. There are informational kiosks around that explain the different buildings and it is quite lovely there. You can easily walk up and down the pyramid steps -- they are a bit more shallow in SL than I remember OR I, as Divine, am more athletic. Perhaps it is a bit of both.The sim Azteca, billed a colonial Mexico, definitely has the feel of the locale and some cute mini tiendas with authentic crafts and such. Unfortunately the shops are scattered among red-taped upper class homes (very authentic - :D) so flying or walking is a bit problematic. I LOVED the graffiti on the walls and posters on the poles. So Mexico and so fun.
You can find some very nice paintings (most likely brought in from the web, but still very tasteful) at the corner of Progresso and Nogales (or 78,24 on your map). There is a bookstore of sorts with Mexican "coffee table" books in a large colonial building called El Rey.
And just as sun was setting in SL and I was journeying off to my comforter and pillows in RL, I found Pelenque. Lush and green at the seemingly top of the world, I gazed down at the ocean and remembered how lovely Mexico can be. I landmarked and will return. DO come visit. It is lovely -- just to sit and ponder!