The A275 runs north-south through mid-Sussex from Wych Cross, a hamlet south of East Grinstead, to Lewes.
Wych Cross - Lewes
Starting from the junction with the A22 at Wych Cross the first mile takes the road out of Ashdown Forest to the village of Chelwood Gate. After a further two miles we come to the village of Danehill. The name is derived from Dene Hill from the Anglo Saxon "Debera", meaning a large clearing in the forest, or a swine pasture, on the hill. The road through the village became a turnpike in 1752 and was one of the main routes from Brighton to London until 1780 when the now-A23 was built which took the traffic away from the village. Continuing southwards, the road passes through the Wealden countryside for another two miles, gradually descending towards the Ouse valley until we reach the two visitor attractions on this road. The first to be reached is Sheffield Park Gardens, now run by the National Trust. These were originally designed for the Earl of Sheffield as part of his country estate and although the gardens have been given to the Trust, the house remains a private residence.
A further half-mile brings us to the river Ouse and the second attraction, Sheffield Park station, the headquarters and southern terminus of the Bluebell Railway. This is the 2nd oldest preserved railway in the country, indeed when it first started operations in 1960 British Rail was still building steam locomotives (the final was one built that year). It is also the only preserved railway which can claim to be 100% steam (i.e. no diesels even for shunting and engineering trains), even though the line was electric when closed in the 1950s. Anyway, back on the road we pass round to the south of the station and some coaches perched rather precariously on the end of the railway embankment (the overbridge was removed and the road straightened in the late 1960s). On the left you will pass a large dairy, the source of the many milk tankers which can be seen using this road, before climbing out of the Ouse valley to meet the A272 at North Chailey. Despite the crossroads having been replaced by two mini-roundabouts requiring A275 drivers to turn right then left (heading south), the junction is still known locally as the "Chailey crossroads".
Heading southwards again the A275 passes through the village of Chailey followed in quick succession by South Street and South Chailey. The next place of significance is Cooksbridge where the road crosses the Haywards Heath to Lewes railway via a level crossing adjacent to the station. Full barriers are provided monitored via CCTV from Lewes.
The final part of the road is the most scenic part as the road rises up to run along the side of the Ouse valley with travellers treated to good views across the floodplain below, although in summer the view tends to be obstructed by tree growth. On the northern approach to Lewes the road splits. Originally the A275 took the left-hand branch and headed down into Lewes town centre, with the right hand arm the A276. Nowadays the A275 takes the right-hand arm with the left-hand arm numbered as the A2029. To remain on the current A275 therefore we must take the right-hand arm which gradually descends through residential areas to finish on the A277 by Lewes Prison.
The A275 originally continued through Lewes and ran down to Newhaven to end on the A259. However, the lack of access to the A27 Lewes bypass caused it to lose its status as the preferred route to the port. Instead the A26 was extended on a route from the bypass along the other side of the River Ouse using the A27 and B2109. The A275 became the B2193 in Lewes and was then declassified from there on.