To get there, follow a rough and rocky dirt trail from the main Uluwatu road (look out for the small blue sign reading "Nyang Nyang surfing beach") to where it finishes at the cliff edge.
You'll see a small shack of a shop and a house and from there it's a 15-minute walk down the 500+ steps that climb the Nyang Nyamg escarpment.
Once at the base you'll see more cows than people and you can set up camp wherever you want. Note you will need to bring your own food and water as there is nowhere to buy anything at beach level -- a rarity in Bali, believe us.
It's a coarse sand, and as a surf beach Nyang Nyang is popular, but this most certainly isn't a novice wave. Uncrowded rides of up to 150m can be had when conditions are good.
This is an ideal spot for a Robinson Crusoe day out, when you really just want to have a lot of time to yourself. Plenty of secluded spots are hidden amid the scrub and shade can be had up on the grassy plateau (which you'll share with the cows). Bring lots of water and food, or be prepared to buy from the old crones at the top.
A word these vendors: if you say you'll buy one of their crummy bracelets on the way back, they'll remember you return — and you will honour your words.