It is very easy to travel Hiroshima - Miyajima. Miyajima is an island, so you'll have to take a ferry to get there. The main ferry terminal on the mainland is Miyajimaguchi (宮島口), which you can reach from JR Hiroshima Station by JR train (¥400, 25 minutes, or ¥570 for a combination ticket with the ferry). From Miyajimaguchi Station it is short walk via an under pass to the Miyajimaguchi Ferry Terminal. There are several convenience and souvenir stores around the Miyajimaguchi Ferry Terminal to entertain you while you wait for the ferry.
An alternative route is by tram line #2 (¥270, 70
minutes from Hiroshima JR Station). The tram line also passes by the
Hiroshima Peace Park and
may thus be more convenient for visitors also touring
There are also direct ferry connections from Hiroshima Peace Park to Miyajima, running once an hour or so from near the Hiroshima Peace Memorial and taking only 23 minutes, but these charge ¥1640 for the privilege.