Nusa Penida is a great place to visit when in Bali. It is nice and quiet, has some beautiful places to see such as the very famous T-rex cliff, and you can easily get around by car or scooter, before sailing back to the mainland. If you are into diving, this is a likely place to see manta rays.
Broken Beach is a famous destination in Nusa Penida, Bali. It is called "broken" because of the archway that allows the beautiful azur blue water to flow into the stunning cove. You can even visit by boat, and there is a chance you will see manta rays in the area. In Balinese it is called Pasih Uug. If you are in Nusa Penida, this is a must see and a photographers paradise.