On the maps called South Hill Barn Car Park. Decent sized free car park, and despite being so busy we didn't have trouble parking. Entrance in at the bottom of the lane for the car park does have some huge bumps to navigate so careful if you have a low car!
Long sloping way down on the way out, big steep hill through the fields to get back. The last section through the field has stiles at either end - they do have doggy doors, and Hank probably is the limit of sized dog that would fit through these. Watch out also, a tiny little Adder crossed the path in front of us, no danger for us but are around here!
You can get to the sea at the beach, is a stone/pebble beach though so not the most comfy to dogs to play in.
Several in and around the car park
When we went was a little cafe in the car park and some portaloos. Lots of different routes to extend your walk and make more of a day of it too, you can walk along the cliffs to Seaford or explore more of the Cuckmere valley in teh otehr direction.
Beautiful place, but I must stress this is a crazy busy place! I did go on a bank holiday weekend in Summer Holidays so I'm sure there are quieter times to come, but lots of visitors and tourists here so just be aware it is one of those places before visiting!
The appeal for so many visitors is clear though, the views over to the Seven Sisters cliffs are incredible and the walk down to the pebble beach at Cuckmere Haven past the coastguard cottages is an idyllic setting, and then looking inland along the winding river valley there's nowhere like it, and is totaly worth it.