Directly opposite Arundel Castle is Arundel Museum which tells the history of the town spanning over thousands of years. It was founded in 1963 by a group of local people who founded the Arundel Museum Society, a registered charity that still runs the museum. It moved to its present location next to the River Arun in 2013. Tickets are £5 though you do get a discount if you show your ticket to Arundel Castle.
Louise Jayne's Blog 