Newhaven West Quay beach
I like Newhaven. A ferry port town with a frontier feel to it.
If though, like myself, you like to hunt for fossils and escaped fishing boat buoys, simply follow the river Ouse to the sea.
Park at the harbour end and follow the beach under Fort Hill. You can't get lost, you can only walk one direction.
Time it so the tide has been receding for a couple of hours and you'll be rewarded with chalk strewn turquoise waters, spooky caves, mysterious chalk carvings and splendid cliff panoramas. The Newhaven to Dieppe ferry is worth watching too.
Just remember to get the tide times right.
Tide Times is a good website and there are plenty of apps.