Merrymount Age

At first it's not much but a mountain. But the large dish on top does not only allow communication and Shaw TV. But it also catches rain. That rain when mixed with a mineral in the age creates an explosion of ice (the bottom of the ocean in this age is ice).
That force can be controlled and fired so that it can create long ramps of snow. Now Eric here can go and snowboard as much as he wants. At the mountain's foot is a cabin with an elevator that brings him back on top (like the one we find in MYST 4 in Tomanha). But he has to hurry every time, because the sun will eventually melt the snow.