Signatures of 17th century stonemasons have been discovered on historic seawalls in Southsea.
The markings were exposed on the sea-facing wall after groundwork on the area's £100 million Coastal Scheme in Portsmouth.
The signatures are known as 'banker marks' and were used to ensure each mason was being paid the correct amount for their work.
Each mason had a unique mark, which they used to gain admission to a guild.
Principal Consultant for Wessex Archaeology Alex Godden said the marks will help researchers to find out if local masons were used when building the wall.
He said: "We may well further identify the same stonemasons' work on buildings in or around Portsmouth, based on their individual marks."