Ke, I can only speak about the Lamanai trip which we took three seperate times. I found the walking not to be that bad and of course your parents can choose whether or not to climb the ruins
( one trip our son was age 4, no problem) I found the tour to be interesting and the Belizean lunch provided was great. Definately worth it IMO. You must be so excited to show your parents around. Have a wonderful time! Rhonda