Last year I found out what those hooks in the walls are for...hammocks (or was someone pulling my leg), but maybe they are just in the place I stayed on Isla Mujeres. Now I'm wondering whether 1) those hammock hooks are found in the downtown hotels on Cozumel; 2) whether those hooks would really hold an adult in a hammock, since most travellers don't seem to find a hammock as a viable sleeping option and the hooks seemed like they have been there forever and just painted over...assuming that they don't get much, if any, use.