Oldest sundials of America ?

[robic.joel]

Greetings fellow dialists,   I want to ask if someone knows which are the oldest sundial in America ?   I can propose 2 old ones from Yucatan in Mexico: http://perso.wanadoo.fr/cadrans.solaires/cadrans/Cadran-mexique.html (as you can see, I have also some questions on them)     Thank you for your help   Joël  48°01' N  1°46' W