Quote - Renderosity is most certainly not the answer, of course. You have to be a member to view.  

Renderosity has managed to get tens of thousands of pages indexed in Google, including some news and image pages, probably by using cloaking based on user agent.

But the question is: do they get ranked?

I post my images on several different websites: my own one (www.virtual-lands-3d.com), Elfwood, Renderosity, DeviantArt and Epilogue. I made a series of tests in Google Images for some keywords contained in my image titles. : only my website and elfwood rank on keywords in image names such as Gauntlgrym, Tantrevalles, Ledo road and elven fortress.

So what does this mean?

If you cannot post on Elfwood, the surest solution is to make your own website, focused on Tenochtitlan or Aztec imagery.
You will be able to optimize it the way you want. The main problem will be getting quality  inbound links and gain enough popularity to rank. It took 6+months for my website to rank on interesting queries for instance.
I think you should also make sure the website is designed to achieve well defined goals. Getting trafic is one thing, transforming it is another. Maybe you could come up with more specific queries containing the Tenochtitlan keyword.

Sorry for the lenghty and OT answer but I could not resist (I am a SEO Consultant in "real" life).

Fantasy pictures, free 3d models, 3d tutorials and seamless textures on Virtual Lands.