The village of Bangli is surrounded by nice jungle and waterfalls. Kuning Waterfall is one of them. It is not far from Ubud, more or less 45min by car (about 20km).
From the parking you will have to walk 30 min in lush green jungle. Getting down the stairs, you will be able to enjoy nice views and you will already see 3 small waterfalls on the way.
Once there you can swim and refresh yourself at the foot of the waterfall and also in the river nearby.