See

Dreamland. A beautiful beach with excellent surfing conditions, especially for intermediate surfers & on big days when other breaks are too big to surf. Right & left reef break, not too shallow and with decent shape.
Pulau Penyu (English=Turtle Island). Boats from Nusa Dua are available, the price is Rp. 100,000 per person. The boats are usually glass boats which you can see the under water view from the boat. Like its name suggests, Pulau Penyu (Turtle Island) is a turtle conservation area. The local people keep the turtle eggs in each traditional conservation houses individually owned them until the baby turtles born, and they will release the turtles when they are grown. Besides turtle, they also have komodos, birds, snakes, bats, etc. To enter each conservation is usually free, but they will ask you to give some money for animal feeding. They didn't mention the amount, but usually around Rp. 20,000. Once you arrive at the island, 1 or 2 guides will welcome you. You also better give them some tips (Rp. 10,000 or Rp. 20,000), although they won't ask for it. Not giving any money basically will be OK, because they also earn money from the drinking shops near the houses.
* The boat owners also provides the service for snorkeling, parasailing and jetski. Price is around Rp. 100,000 per person.