Kotanali,
Yes the Hol Chan Park fee is 10.us for thoes 12 and over.
I'm sure there is a rule that you have to be accompanied by a licenced Tour Guide.
Mexico Rocks hasn't officially been declared a Reserve and we have no park fee as yet.
I hear form the powers that be, when it is declared a reserve the same Hol Chan ticket will be good for both destinations.
This could happen very soon....well truthfully it's been in the works for 20 years and all I hear is Soon, but like I said 20 years and I feel a little foolish believing them this time :-)but I kinda think maybe this time they really are :-)