St. Denys Church is the main church in the town of Sleaford. Keeping watch over the Market Place, the church dates back to around 1180, judging by its stone spire. However much of it has been rebuilt after a storm in 1884. Features of the outside include a number of stained glass windows, some carved heads and a small graveyard. Inside, the church is spacious and contains an altar rail by Sir Christopher Wren, a donation from Lincoln Cathedral.