one of my favourite places to walk is just on the edge of plympton in plymouth. from marsh mills roundabout take the plympton turn, down plymouth rd and go onto glenn road, then turn left into strode road (anyone who knows plymouth knows this is where chaplains is!) follow the road to the bottom and go right at the roundabout, follow it along untill you see a sign for newnham park (about 1/2 mile) turn left and follow the lane carefully, as its quite tight in places and is used by heavy lorries a lot!
you will go over a cattle grid, (its the only one there so you cant miss it) its here that you can park on the right.
now the good bit!
you will see a track leading onto the moors follow it along with the wall on your right, and the track will turn hard right, if there are no other cars in the parking area you can freely strip off here, as the track is pretty much covered from view from here on in.
If cars are parked up be careful, people will be walking their dogs and they can just appear from almost anywhere. The track will open up onto the open moorland and you will see a metal gate at the top of it, go through it and get your binoculars ready, deer, herrons and hawks galore around here.
If you look over to the left you will see the quarry, and the damage that they have done! and a big hill. walk over there its a good place for a bit of shelter from the wind which can be a bit strong at times. Again there are plenty of tracks you can follow, some go to the river (about 30 min walk) or you can go the other way to cornwood, which will take about an hour but remember here you are skirting around the edge of a working clay quarry.
Back to where the big hill is. I have met and chatted to a few bird watchers here, they are always friendly, alas the horseriders which occasionally pass dont seem to be quite as friendly. But dont let that put you off, I have been walking here for about 20 years, in all that time I have seen maybe 30 people in total, and had maybe 5 "moaners" you can normally see anyone coming from miles away, also if you follow the fence of the quarry around you will find the foundations of an old building that was there, there are some beautiful views for photos up there too
hope this is helpful to someone who lives nearby, and may have missed this little gem of a place.
Oh before i forget, dont do what I did, and sit on the top of the hill watching a thunder storm roll across the sky, when the lightning hit the ground not far from me, and i saw the dust cloud it left, i thought maybe this isnt the best place to be sat!  ::)