A must-do walk with spectacular views and a mixture of flora and fauna - look up the different plants and mammals you see in our wildlife books.
Take a drink, a snack, your camera and binoculars, if you have them.
Although it is called Deer Park there are no deer, just Welsh ponies.
From the house go around the one-way system until you are out of Dale and take the first left to Marloes. Drive through Marloes and keep going until the end of the road where you will come to Martin's Haven car park, which is owned by the National Trust (free for members but around £4 for non-members).
At the far end of the car park go through a gate onto the road. Go left down the hill, passing the café gift shop and toilets on right (not always open). If you follow the road down until the left bend instead of going down the road in front of you will see a gate in the wall signed Deer Park - go through, walk up the hill and you are on the park.
Follow the path round the coastline of the Deer Park, enjoying the views of the off-shore islands: Skokholm lies to the south (on your left) and Grassholm with its gannets is on the horizon. The treacherous waters of Jack Sound lie between the Deer Park and Midland Isle.
If it's not too breezy, sit for a while and watch the seabirds. The rocky bays below the cliffs are used by seals. Look out for seal pups in late summer and autumn - about 50 Atlantic grey seal pups are born each year on the beaches around the peninsula. You can view them from the cliff top without disturbing them.
At the far corner of the Deer Park, climb Wooltack Point for spectacular views across St Bride's Bay. This is a popular spot with sea anglers: pollock, wrasse, mackerel, and even conger eel are regularly caught.
The heathers and flora are very interesting and some plants can only be found on the Park.
Climb to the coastguard hut. This is now an active coast watch point operated by the National Coast Watch Institute. Enjoy the views - this is a great place for a picnic on a sunny day.
Follow the path down and back towards the car park. The path and steps pass through the ramparts of a 3,000-year-old Iron Age coastal fort.
At the gate in the wall, turn left for the Skomer Marine Nature Reserve Information Centre and boats to Skomer, or carry on up the hill and back to the car park