The postcode will take you to the quarry on Water Lane, the entrance to the National trust car park is directly opposite this on the other side of the road. Fairly bumpy entrance to car park.
This is a hilly walk! There is a large fairly flat area in the centre but to walk the perimeter and get from the car park there's lots of steep hills, and muddy, sandy, bumpy trails which can be boggy in wet weather.
No water here
Poo bin at the entrance to the walk right off the car park.
Close to Storrington Village centre, and there are lots of footpath entrances to the Warren from residential roads too so it's possible to park in the village and walk here if you want to visit there too. There is an entrance just off the sharp bend in Woodpecker Lane.
This isn't a huge area, but a half hour walk round the perimeter feels like you've gone a lot further than you have as you are up and down the steep hills straight from the car park!
You are fairly close to the residential areas that surround it, but in truth once you're in you feel a mile away and the tall pine forests, lowland heath and huge, flat grassy open area in the centre make for a very scenic walk in all seasons and it's very pretty. As you reach the top of the hill from the car park, it's very easy to follow the pathways and you can go left or right to create a loop, take a mental picture of where you came up though as when you come back there are several paths that look similar.
You're well away from the roads too so plenty of off-lead opportunities, it is however a popular dog-walking location so if like Hank your dog rushes off as soon as he see's a potential playmate then like me you may have to keep him on the lead for much of the duration. That said, being such a dog friendly place I've always found people here very friendly, and even today I met a nice couple who were very kind and happy to have Hank off the lead playing with their dogs so a good place for socialisation too.