DS has made a new friend through mutual school friends. He doesn't go to his primary school but IS going to the same secondary school in September. They're 11 years old.
Since DS met this lad they have been going off on their bikes to a particular park near the other boys' house. Near the park is a field with horses and beyond that, a wooded area and a train line.
I'm not sure why I'm frightened but I am. They can't get on the trainline and I would hope he would be sensible enough not to try (I've told him horror stories of people getting trapped/electrocuted/hit by trains and have also warned him that CCTV covers ALL trainlines and he is at an age where he can be arrested for trespassing) so I don't think he would dare go on the lines. So why am I so fearful? I used to play in the same wooded area when I was younger than him, often on my own. It has little streams, little wooden bridges - the kind of stuff you'd expect to see in a horror film 
He went out at 9.30am and didn't come back until 7pm (I kept in constant contact via text message). When he came back he told me he'd played in the park with his friend, been BMXing, fed the horses (big clumps of grass, nothing else), played in the forest, built a dam, been to chippy courtesy of the other boys mum - and when he got in he fell asleep on the sofa!
I'm torn between been pleased he's living a "proper little lad's life" and been frightened something will happen to him 