The button-shaped, jungle covered islands Rock Islands were nice and interesting to see above the water as we cruised around on our tour, but the real attractions are below the surface.  The absolute highlight, of course, was Jellyfish Lake, which, as of our January 2019 visit was back in business and open to the touring public. Snorkeling with these eerie creatures was incredible.   We had two days out among the Rock Islands. The first afternoon we went kayaking with a little bit of snorkeling at a couple different spots.  Kayaking was a lot of fun and we were glad we'd decided to do it. The next day we did the grand tour, which included: the Milky Way (you cover your skin with smooth limestone mud from the sea floor); snorkeling at several spots such as Clam City (Giant Clams), the "Big Drop",  Jellyfish Lake, and more; lunch at the scenic Long Beach (an island with a very long, smooth sand bar); and boating beneath a nice rock natural arch.  The snorkeling was fantastic with lots of variety of coral, uncountable colorful tropical fish, sea turtles, rays, starfish,... It was probably worth it even without the jellyfish. But with the jellies included, we were all smiles.

 

We booked our tour through the Antelope Guest House and were very happy with the service we got. We were the only guests with our guide both days, and had Jellyfish Lake all to ourselves for most of the time we were there, though a bigger group did come along when we were about 3/4 the way through our time there.  The price of our tours was about the same as the bigger agencies, but it was nice not being in a big group.  Jellyfish permits are currently $100 which is good for exploring the Rock Islands for 10 days. We were told they are considering raising the price.  There's a lower cost $50 Rock Island permit to see the rest of the islands if you don't go into Jellyfish Lake. They ask you not to put on sunblock before entering Jellyfish Lake and try to rinse people off a little bit.  We had the sunburns to prove our commitment to the survival of the jellies (but they think it was more the natural El Nino effects that caused their decline (down to nearly zero) rather than sunblock chemicals).

The Rock Islands were really a fantastic experience. Palau in general was really great, and the Badrulchau Stone Monoliths at the north end of the main island would probably be of interest to most people on this website and I was happy we made the effort to see them.