Parking is along Mill Road, or if busy as it can be at peak times there is also a large pay and display car park on Mill Road by the castle entrance.
Stick to the perimeter walk and it's pretty much gravel and chalk paths the whole way, and mostly very flat with any slopes pretty gradual. If you want a longer walk then there's mud and grass paths and can be very steep.
There are several points with shallow access to the water, but do beware of lots of wildfowl and swans.
Several bins by the main entrance and along Mill Road.
Very close to Arundel town centre. Is also close to the wetlands but dogs aren't allowed in there.
Swanbourne Lake is a popular place to come for families and people visiting Arundel, and there's a nice little cafe and row boats for people to hire. The path around the outside of the lake is a nice place for a dog walk too, and whilst there aren't wide open spaces so is a lead walk it's a pretty area and there are several routes to extend the walk too if you want.
At the far end of the lake there is a path that heads north through grazing fields. and also a path up the steep hill to Hiorne Tower which we took. This path isn't too far, but is very steep so quite an effort - there isn't access to the actual tower from this direction but a nice view point once you're at the top.
Arundel is a beautifiul town to walk around with its cathedral and castle, so plenty of places to explore if you want to make more of a day of it.