Lake Buyan is one of the prettiest spots I've seen during my two-day motorbike trip around Bali.
It's surrounded by rice and coffee plantations, the road itself is quite exciting while on a motrbike- very curvy and constantly taking you higher up. I've seen two observation desks, one to the side of the road with a monkey population to make the stop all the more fun. The second one up the hill, with some benches to enjoy the panorama from, and a restaurant across the street to enjoy a cup of coffee in.
There's also another lake closeby, Lake Tamblingan, if you continue to the western end of Lake Buyan.
