At the top
At the top you will have a great view of the valley below (not the lower falls unfortunately), but the pool at the top is a great place to soak your feet while you listen to the rushing water of the upper cascades and eat your lunch, which always seems to taste better after a strenuous climb.
After you have fully relaxed, head back down the way you came. It may be a harsh if you have knee problems, but the hike down is almost guaranteed to be much quicker than the hike up.