When Amanda and I were at Bonampak this September, we ran across this Nephila clavipes. It was in a web on the side of one of the buildings at the top of the temple structure in the bottom photo. With it's legs spread out like that, it was bigger than my hand. It is a female, there was a much smaller spider below it on the web which I'm pretty sure was the male.
The famous murals of Bonampak are found in the building to the middle-right.