Stanmer woods are odd. When I lived in Brighton, I would often go there, sometimes with friends, sometimes on my own. As you say, not creepy as such - but something that never feels quite right. It always had a 'late afternoon' feel to the woods, is the only way I can describe it.
A couple of miles away from Stanmer Woods is Wild Park (another wood rather than a 'park') - just on the very edges of Brighton. A loathsome place, and it comes with a bad history of the 'babes in the wood' murder back in the 1980s. I went to Wild Park with a friend back in autumn of 2006 on a grey autumn day. Loathsome is the only word to describe the atmosphere there. The air felt toxic and rotting. Maybe we had the thoughts of the murder in our minds - but I've visited other places with bad histories but nothing that had an atmosphere of poison that Wild Park had. The atmosphere caused a bit of panic between me and my friend. We were relieved to leave it. As we walked out of the trees my friend turned to me and said - and I still remember that tone of disbelief inhis vocie 'why would anyone want to come here?'
Wild Park. What a God forsaken place that is. The woods has a feel like something out of a Tolkien book.
I used to live in a part of Brighton (UK) next to Wild Park, which is on the southern edge of the South Downs, called Mouslecombe.
Named after a minor Saxon warlord called Mul. A combe is a Saxon word for a place that is enclosed on three sides by hills. Mul of the Combe. There's arguments in some circles as to the correct spelling. Mulscombe, Moulscombe, Moulsecombe, etc. Wild Park forms a combe, open at one end and enclosed by hills on three sides. Curiously enough, the Saxons would not settle in a combe that faced East, which Wild Park does.
Locally Wild Park had a reputation as a place to stay away from for no particular reason I ever heard of. The grassed flat area was fine but the woodlands surrounding it on three sides were more than just creepy, they were/are downright unfriendly and of course and as you mentioned, the 'Babes in the Woods' murders. There are now some steps leading to where the bodies of the young girls were found and even now, flowers still get placed there. God rest their souls. It's one thing to read about such grisly things but another to see the actual place.
Once I looked after a neighbours dog while him and his wife went on holiday and as Wild Park was so near, I thought to walk the dog in the woods. On the grassed area the dog, a spaniel type mongrel, would run all over the place at speed hunting down smells and scents but as soon as we went in the woods the dog stayed right next to me. I kept looking around me because I just had a constant weird feeling of 'not alone'. I never saw anyone else, which is strange in itself, or saw anything odd or untoward. The feeling of 'unease' was tangible. At the time I put it down to my mind playing tricks on me. After the third or fourth day I decided to switch to Stanmer Park for dog walking although it meant a short drive. The dog seemed happier with that as well. After my neighbours returned from their holidays, I said about Wild Park and the wife said she never goes there. I don't remember any reason being given.
There used to be a cafe in the middle of the grassed area that would change hands almost yearly and stories of weird goings on there. I would eat there sometimes. Once, and this was during the nineties and at the time I thought it made up stories, the lady who ran the cafe said she wasn't renewing the lease when it runs out in the next few months. She said that odd things kept happening like coming in in the morning and a table would have moved several feet from where it was when she left the evening before or things just falling on the floor from a surface or shelf and stuff like that. At the time I thought it was just a reason to cover up a failing business or something like that. Now though, I'm not so sure.
At the time I didn't connect the dots. My 'Fortean moment' came in the early 2000's one evening when I saw what looked like loads of candle flames at the end of a friends rather large garden. I was sitting in his conservatory chatting away with him. I said to him about it and he said he and his wife and others see them from time to time and several times he'd walked down the garden but the lights go out and there's then nothing to see. I did the same and the lights went out and even though it was nearly pitch black apart from the lights of the house, there was nothing to see. I was convinced it was kids or something even though the wall at the end of the garden was substantial and it backed onto the South Downs and was out of town. It piqued my curiosity. It was after odd times of doing a search for similar, and I found some some similar stories, that I came across this forum although at the time I didn't post anything about it for fear of ridicule as it wasn't mainstream ghost stuff, etc.
There's also been sightings of an ABC at Wild Park. Once by a group of dustman that got local publicity. They'd parked up near where the woods start and where the land starts to go uphill and were having a fag break early in the morning at dawn. One of them said to the others something like 'what's that' and skirting around the edge of the woods was a large ABC. There have been numerous sightings over the years I've lived here including one by two park rangers in broad daylight in the woods but none in the last 5 or 10 years that I know of.
There's more about Wild Park. I think I've written too much already for one sitting.
Edit: Loads of missed out words and stuff I forgot when typing it out.