The A1121 is a rural link road in south Lincolnshire.
The road starts at a mini-roundabout on the A52 at Chain Bridge, on the western edge of Boston. It heads westwards, with the single-track Sleaford to Boston railway line immediately to the left and the South Forty Foot Drain immediately beyond that, although it isn't really visible. An out-of-town retail park is on the right initially but we soon enter open country. The road is dead-straight and the land completely flat.
We soon reach Hubbert's Bridge, where the railway line becomes double-track just before the station. The B1192 crosses us here and goes over the drain to the village centre: we hardly pass any buildings but there is a golf course. Road, railway line and drain then bend to the left unexpectedly, then we continue dead-straight once more.
A1121 Near Aby Farm, Swineshead Bridge
We cross a side drain before passing a plant nursery and crossing another drain. Then the road bends to the right, diverging from the railway line and South Forty Foot Drain which still run next to each other. We enter the hamlet of Swineshead Bridge at this point and end shortly afterwards at a T-junction on the A17 just to the north of Swineshead station and the eponymous bridge over the drain.
This road was unclassified in 1922 but was soon given the number B1371. This survived until between August and November 1962 when the road got its present number.