Is it for a holiday or some kind of project? I know someone cheekily said Brighton but you could literally pick anywhwere between Brighton and Eastbourne on a grey day and it’ll be pretty bleak, like Rottingdean, Peacehaven, Seaford, Newhaven (or Worthing on the other side)
There’s also a patch of the pebble beach in Hove-Portslade that’s a stones throw (wey) from a live, open sewage plant which is about as bleak as it gets