The rugged cliffs of the Royal National Park can be reached by driving to Bundeena. Park at the end of Eric Street and enter the Park via the service road. The trail head is well-signed and will take about ten minutes to reach the coastline. From here you can walk north to Tumbledowns, Jibbon Point, and back to Bundeena. To the south is The Balconies, Marley Beach, Wattamolla, and beyond.
If this point is as far as you get, it's worth it. The views of cliffs and ocean are magnificent and eminently photo-worthy. The rocks underfoot are interesting and shaped by wind and rain.
There is a well-worn trail that follows the dip and curve of the coastline, narrow in parts and board-walked in others. It's worth the trek to Marley where you can rest on the sandy beach and enjoy a picnic if you brought one. Wattamolla has all that plus toilets and a carpark where you can be picked up if you don't want to walk all the way back to Bundeena. Allow a day for this trip.
It's a popular and relatively easy trail, and there are cafes in Bundeena waiting for returning walkers. If you need something stronger than coffee, there's also an RSL and a bowling club.
3 quick tips: 1. Wear closed in shoes to protect against sticks, stones, and bull ant bites 2. Bring water