Baltic Wharf Caravan Club site at Bristol. Not a city but Southport Caravan Club site. Again not a city Four Oaks Caravan club site at Henley-on-Thames.
Hamer
Hi,
there's a site at Sofia Gardens, Cardiff which is a 10 minute walk through the grounds of Cardiff Castle to the city centre. There's a river bus that you can take to the bay area. Great location,
Homer
Norwich C&CC site. I understand it's about 25 minutes walk, mostly along a footpath that is a dis-used railway track so no traffic.
Sites alongside a river.
Oxford C&CC site is within a short bus ride of the city centre with it's universities, pubs and the River Isis. The bus park and ride terminal is opposite the caravan site.