Firstly, sorry if this is a little bit scattered or confusing. I am still trying to get my head around the facts myself so I'll try my best.
In June, my friends and I went on a trip to the coast, for four nights. We stayed in a room with 11 of us, in a hostel of sorts. My bed (a bunk bed) was pushed up right against the wall, so there was no way anything could get down there as I couldn't even fit my hand through the gap. Keep that in mind.
On the first night I awoke in the middle of the night. It wasn't due to a noise or anything, I just woke up. I turned to the wall and saw a woman hanging down my bed, in a white night dress with long dark hair, covered in blood. I screamed and grabbed a torch to look closer, but nothing was there. My friends all woke up and asked who screamed, but I was too scared to reply. I thought maybe my friends were pranking me, but how could anything fit down the side of my bed? This only happened once so it may have been a dream but it seemed so real. I told my friends in the morning and they all swore it wasn't them.
The next day a lot of our stuff went missing in the morning - clothes, money and purses mainly. No one apart from us could get in the room, so who could have stolen it? We came back several times during the day and we couldn't find any of our stuff. In the evening we got back around 11pm. All our missing stuff was in the centre of the room. Most of us were starting the think the room was haunted. The only explanation for this is (other than someone stealing and replacing our stuff) was a poltergeist. I've read that poltergeists often feed on the energy of teenagers going through puberty, so it'd make sense as there were 11 teenagers in the room.
That night we all noticed a shadow figure by the door, maybe 4 or 5 foot tall. It was in the shape of a male human. This trip was hosted by an all-girls school so there were no boys residing at the hostel. The door knob began creaking which was very unnerving. After a while the shadow disappeared.
The next night was the worst. In the night around between 12 -1am, I went to the bathroom. I felt a very strange energy. There was a mirror right outside the bathroom and I looked in it, and saw a tall dark figure standing behind me. I ran into the room feeling really unnerved. I told my friends and they were beginning to feel scared too. I decided to sleep in my friend\'s bed. We all fell asleep until we were awoken by a scream. My friend in the bunk above had been woken up to her head being yanked backwards. Her hair was in a high bun and all her hair has been ripped out the band and the bun was right at the bottom of her head. We were too scared to sleep so we stayed up. Then, we noticed a human figure by the door again, like 6 or 7 foot tall. It moved around the area and we were all so scared and half of us were crying. Then a girl across the room sat up and stared at us all. Someone joked "she's possessed." Her eyes were glazed over and she kept staring, even though we tried to snap her out of it. I'm almost 100% certain she wasn't possessed but I don't know what happened. It took about 6 minutes for her to snap out of it and she didn't remember it happened.
On the last night, nothing too scary happened. We heard some distance laughs and screams but it might have been other people so it wasn't necessarily something paranormal.
Throughout the stay me and another girl ended up covered in cuts and bruises that appeared overnight. The bruises were like fingers gripping us and the scratches were like nails. It happened most severely to the other girl, whose family has had experiences with the paranormal (her mother and grandmother). We aren't experienced with ghosts and the like so we were very afraid, which may help you provide an explanation?
So yeah that's it. I would appreciate if anyone could provide explanations. Again, sorry it's a bit hard to read, feel free to ask me to clarify stuff!