Illustrated is one of the piers flanking the entrance to Bristol Gate from Eastern Road, erected mid-19th Century. They were Grade II listed in 1999 and the pilasters are described as being in the Tuscan style. I would have said Doric but I'm not an expert. There are no visible indications of hinge-fixings so they may never have supported gates; indeed with only a rubble core they may not have been strong enough to bear the necessary cantilevered weight. Their function therefore was probably purely ornamental.
Also listed is the low wall attached to the eastern pier. Both piers are in poor condition with the rubble core exposed in places. They are intriguing architectural history markers. One hopes they will be protected from damage by large machinery during the forthcoming and lengthy Royal Sussex County Hospital development work.