Good point re: checking tide schedule/times at Miyajima. It’s fun to be able to walk to it, but also take photos with it “floating.” Also cool to see the water underneath the shrine.

If you plan it right, you will be able to do it all in a day trip from Kyoto… couple hours in Hiroshima (peace park, eat Hiroshimayaki), a good 5-6 hours on Miyajima (Itsukushima shrine at low and high tides, ropeway to top of mountain with a bit of hiking). It will be a long day but, if you limit the number of sights to visit, it will not be too rushed.

The atomic bomb museum is one of those places you may or may not decide to visit. I went once and it was quite depressing. But at least go visit the peace park and the dome building.