Aidan, Merchant Rock is really quite good and easily accessible. If you head down Conto Road (off Caves Road) you will come to a parking area, just walk towards the ocean from there on established tracks and boulders are everywhere. You’ll appreciate having a crash pad for a lot of this stuff as the landings are on rock and not sand!
There’s also an area only accessible by 4WD called Juniper Road- it’s off of Caves Road too and north of the turn-off for Gracetown Caravan Park. I’m reasonably sure that Juniper Road would be on a map, but I’ve only been there once so maybe someone else can provide more info!