Below my sister's place is a salmon spawning stream/river that is perfect for taking little boys on an nature walk. We came to this cave-like tunnel at far end of the stream, which keeps the water flowing through while holding train tracks above it. The boys and I ventured through the dark tunnel, finding an almost magical waterhole on the other side. If I had had my video camera with me you would have heard me 'yelling' at the boys to be careful along the wall and sides- not to slip into the water because it was so deep. They are OK swimmers but it would have required me jumping in after them, camera and all if they had slipped in. No worries- all went well and they have an adventure story to add to their summer holiday journal.