If you are on Bali, you must see a Monkey forest it is one of the most popular and one of the most quietest places on the island. It is cheap (~2.5$) and attractive. Monkey forest located near Ubud. It isn't big. The best time to see it is a midday.
Monkeys meet you on parking. They are jumping on scooters and walking through the parking, so be cautious and attach helmets to the scooter. Monkey forest has a lot of interesting architecture forms: temples, dragon bridge, pond and lizards sculptures.
All temples in monkey forest are closed for visitors, they are opened only for prayers, but monkeys don't have any rules.
Dragon bridge is awesome, it fits perfectly into nature.
In the pond live catfishes and goldfishes. The pond looks like a small oasis, the water is crystall clear.
Monkeys are everywhere, you shouldn't be scared because all monkeys are doing their own "monkeys business". If you don't touch them, feed them by yourself or have a long eye contact I bet no monkey will harm or even touch you.
To have a contact with monkey you should ask a forest officer to help you, it's free. You'll get an excellent experience.
Monkey forest gives you unique opportunity to see monkeys in their natural enviroment without any barriers.