Part of Colchester's ancient Roman wall has been uncovered.
Parts of the South Gate were discovered while gas mains were being laid by Morrisons in Queen Street, Colchester.
Philip Crummy, director and chief archaeologist of the Colchester Archaeological Trust, said the remains found showed the original Roman gate had been remodelled in medieval times.
Mr Crummy said: "We have been monitoring the gas works and came across the South Gate in the town.
"We know that was pulled down in 1818, so this is the first time anyone has seen it since then.
"It is quite interesting and gives us more information.
"It looks like when they rebuilt it in medieval times it must have had towers.
"We can see the foundations with the peg tiles so we can tell it is not Roman.
"We would have liked to have seen a Roman gate but this is just as interesting."
The gates into Colchester were torn down about 200 years ago to allow the roads to be widened.
Parts of the East Gate fell down before the rest was removed. The Head Gate was taken down in 1760 and the South Gate in 1818.
Mr Crummy added: "There were also some Roman remains at the South Gate which were probably used in the remodelling in the 13th century, if not later."