Active attention

Active attention. A constant awareness of what is happening inside and outside. Then desire comes. There is just a watching of the desire. with curiosity even. And watch. The desire comes and goes. Our awareness is like watching trains come and go in a railway station. Im not going into any of the trains. I just watch them as they come in and then watch as they go. This "watching" is more a sensation, a tugging. What is this sensation I wonder. And where is it happening? Inside the body or outside?