Norfolk is so big, that great swathes of it are little known. In the area between Wymondham, Dereham and Norwich there are perhaps fifty medieval churches, but only a handful of them - Ketteringham, the two Tuddenhams, Ringland - ever make it into the guidebooks. And yet, in any other county, Colton would be better known.

Take a look at St Andrew. Externally, it is what most East Anglian churches must have looked like in the early 14th century, in the years before the Black Death and the consequent rise of Perpendicular architecture. The Early English tower from the late 13th century, and the flowering of the Decorated style in the early 1300s, have left their mark in the window openings. But don't look too closely, or you may detect that some of them are, in fact, Victorian replacements.

But the fact remains that not much happened here after 1350 until the Victorians came along. The graveyard is long and narrow, carved out of the fields around, and you might think that perhaps there was once more of a village here. We came on a fairly dour February morning. In fact, against all forecasts, the sun would come out while we were inside the church, and we'd emerge to an almost spring-like warmth. But we had stepped into an interior smelling of wood and stone, and as our eyes became accustomed to the light they met the glow that any church would get from such a magnificent west gallery.

It was built as late as the 1850s in an unashamedly Gothick style, a gift of the Daveney family whose ledger stones pave the nave and chancel. The organ, for which it was constructed, rises like a sea monster from the waves, and the gallery is fronted by brass eagles on perches. You can climb up to the gallery, and it is worth doing so, not only for the view eastwards and the close up of the George III royal arms, for there is a rare survival in the form of a wall painting on the west wall.

It is just to the north of the organ, and was uncovered during redecoration in the 1930s. It depicts the Warning against Gossip, a popular late 14th century teaching tool designed to depict a dangerous occasion of sin. Two women sit on a bench ignoring their rosaries but having what East Anglians call a good old yarn. Devils encourage them by pushing them together, meanwhile writing down on scrolls the things they say, doubtless to be used in evidence against them on the day of judgement. You can see the painting, and a detail of a devil, on the right. As I said, the Daveney family have left their mark on St Andrew, but it is a Pooley that dominates the nave. He is Philip Pooley, who died in 1715, and his memorial in the north-east corner of the nave depicts his head and shoulders life-size in effigy. The more restrained memorial beside it is to his wife.

The church once had aisles, but the arcades were removed to widen the nave, states Pevsner categorically. This seems like nonsense to me. The nave simply isn't wide enough to have had arcades, and what appears to be the medieval rood beam still crosses the church from wall to wall under a later roof.

Curiously, the southern third of it is castellated; you can see this in the image on the left. Is this why Pevsner thinks there was originally a wall division between the castellated part and the rest? Without actually getting up there and taking a look, it is hard to know what has happened. Either the castellation once went right across and has been removed, or it formed part of a canopy of honour to an altar in the south-east corner of the nave. St Andrew is a church of light and shadow, the interplay of air, stone, wood and metal. In front of the delicate screen, with its wheels in the ogee arch above the entrance, hangs a brass lamp. Above, an Art Nouveau wrought iron rood completes the piece perfectly.

Some of the benches also appear to be old; a pair of two-headed goats butt each other in symmetry either side of a poppyhead. As the sun comes out, the light in the church changes from white to rose, and the freezing air is suddenly full of the promise of warmth to come.

Simon Knott, February 2006