Colchester has many historic buildings, more than anywhere else in Essex and for much of the country for that matter, but one which most are unaware of is just 200 yards from Colchester Town Hall.

And even for those who know of it, relatively few have ventured inside to admire what, to my mind, is a gem in Colchester’s treasure chest of old buildings. I describe it as the equivalent of finding in the loft a family heirloom which you did not know existed.

The first time I visited after extensive restoration work, by The Churches Conservation Trust, I marvelled at the beauty of what I was seeing – medieval architecture which had hitherto been covered with black paint.

Hidden away in the Dutch Quarter, in West Stockwell Street, is the redundant St Martin’s Church which held its last service in 1953. The final meeting of the Parochial Church Council was in the May – the same month as The Queen’s Coronation – after which the church closed.

St Martin’s was one of eight medieval churches inside the Roman Wall. In the 1950s the decision was taken to close four of them – Holy Trinity, All Saints’, St Nicholas and St Martin (St Runwald was demolished in 1878).

It was not until 1957 a new use was found for St Martin’s Church – it was transferred to the Colchester Theatre Group, under whose stewardship the interior was painted black with a stage erected at the west end.

It was used as a theatre for 30 years, which is how I knew it, but in 1987 the building had deteriorated to such an extent it was declared unsafe for public performances. The theatre group moved out.

There then followed almost a decade of uncertainty for a building which, over the centuries at different times, had experienced problems with its structural condition – and which, according to a plaque in the church, still displays the damage caused during the Siege of Colchester in 1648 when cannon balls fired by Parliamentary forces into the town knocked down the top of the church tower. What was left was repaired but the tower was never rebuilt.

Much of the material used to build the tower, and parts of the church walls, was distinctive Roman red bricks taken from the ruins of buildings which were up to 1,000 years old.

Nearly 20 years ago came a change of fortune for St Martin’s Church, as described in a booklet chronicling the life of Christian worship on this site going back at least ten centuries.

”Its future was finally secured in October 1996 when it was vested in The Churches Conservation Trust, to be conserved and cared for with Government and Church Commissioners’ money as an historic and holy place and an important part of Colchester’s rich heritage.” So wrote Roy Tricker, the trust’s field officer from 1991 to 2002.

It was after the trust had completed the restoration, in 2003, I next visited St Martin’s Church. I have made many more since to admire its interior and to enjoy the tranquillity in an historic building two minutes’ walk from the bustling town centre.

There is so much about the history of St Martin’s Church which only a visit can do justice, aided by the official booklet which conveys so much information. It is open most days, with free admission.

The Churches Conservation Trust is also responsible for St Leonard-at-the-Hythe Church, the Audley Chapel at the former St Michael’s Church off Berechurch Hall Road, the church of St Mary the Virgin at Little Bromley and St Mary Old Church at West Bergholt.