Some of the most amazing diving in the world is here. Dive with the Matas and Molas in Nusa Penida, Macro Dives in Amed and Tulumben or travel to Komodo Island to spend a few days diving there and visiting the Dragons
Well when it comes to hiking there are a lot of things to do but some of the more popular are sunrise Mount Batur hike, for the bigger hike there is Mount Agung and for a multi day hike you can always go to Lombok and climb the volcano there... Also there are local Hash runs with end with beers and laughs...
The Setia Darma House of Mask and Puppets is amazing. Then there is the Agung Rai Museum of Art and last is the Blanco Museum
make sure to have an international drivers license from your local AAA office and travel insurance
There are 17,508 islands near by so do be afraid to go explore around if you have the time