Southwick Hill is probably most known for the tunnel for the A27 that goes under it. It also seems to be a major link for a lot of footpaths. There is quite a wide network of paths that can take you up and around the hill.
Public transport links are quite good. The 46 bus can drop you right at the top of the area right by the countryside, get off at the Overhill stop. Alternatively the 1x will take you to the Mile Oak side of the hill. Stops that have access are between Mile Oak Gardens and Chrisdory Road will get you within walking distance of a footpath to the countryside. Alternatively you can take the Mid Sussex Link footpath that will take you up from Fishersgate station or it’s about the same distance from the better serviced Southwick Station.
There is not really any dedicated parking near the area but most of the streets are fairly easy to park on, especially if you don’t mind waling a bit to the footpaths.
There are three main routes that take you up and over the hill.
The route straight up the middle takes you down to a lovely valley. The south-west to north-east route gives you great views over the Holmbush Shopping Centre and a rather challenging hill up towards the dyke. The final main route is the south-east to north-west route the ultimately will take you to the YHA Truleigh Hill, where you have toilets, food and drinks. If you want this route goes all the way down to Fishersgate station and is a good hour and a half walk, continuously uphill. Though at a gently grade.
There is also quite a network of smaller trails and paths that link up these main routes. At the top of Mile Oak there is a farm shop that serves food and drinks during the day. It might be just me, but I do love standing over the A27 tunnel and thinking of all the cars underneath. Which nicely leads on to the fact that the tunnel also makes Southwick Hill one of the few places around town where the drone of the A27 is minimal. Though the power lines that go from the power plant to Gatwick are a prominent overhead feature on most of the walks.
There are good views of the harbour, the wind farm, Brighton and beyond Worthing. If you follow the routes to the top then you are treated to a view of the lowlands to the north and London beyond that on a good day.
Which you can also see if you take the mostly downhill route from Devils Dyke. Buses run to the Dyke most weekends and some holidays. Then it’s a few hours walk with the hostel nicely at the half way point. At the end jump on one of the buses or continue down the hill to the station.
Plenty to see wildlife wise. Animals from rabbits to sheep and cows to crows. It’s a good place to catch the birds of preys and lots of berries along some of the trails too.