The Kesteven-Holland boundary is formed by the South Forty-Foot Drain, the main land drain of the Black Sluice Level. The present layout of the drainage dates from the Act of Parliament of 1765 but this part of the South Forty-foot is a re-use of one of the main drains of the Lindsey Level, a scheme which was declared complete in 1638. On the other side, in Pinchbeck North Fen, the road begins to wind, something quite unusual in these fens. It was laid out on the bank of a soak dike called the Weir Dike, which was cut in about 1600. In Pinchbeck North Fen, the dike is now largely defunct. The instructions stipulated that it should be at a distance of 100 feet (33M) from the bank of the River Glen. As the river bank meandered a little, so the road does(13).