The Big Loop is a road through the mountains near Chiang Mai. The Loop is definitely recommended to do on Scooter. Asking your hostel/hotel should be enough to find someone who will rent you scooters, with or without a license. The Loop has an elephant sanctuary, dense forests, and magnificent views.
At some point you will see a sign for a temple off the road. It always has busses of monks going straight down from the main road. At the bottom of this small road is an old temple built above a waterfall/river. It is somewhat in ruins, but still pretty cool. There are monks there that are eager to take the few foreigners, that accidentally find the place, on tours/prayers.
There is also a massive river that has 7 waterfalls. Like the temple, it is near the end/beginning of the Loop. You can hike to the top and loop around. There is also a cave pool, but I don’t know exactly where. We bumped into some people who said it existed on the Eastern hills of Chiang Mai (opposite of the Big Loop).
Really the Big Loop is meant for exploring…so go explore!
More Info: GT Rider (the preferred source for the Big Loop)