You don't need to be surrounded by nature to observe nature. Nature is all around us. It is in the ingredients that sit in front of you before you eat your lunch. It is in your very own being, your body, the way oxygen flows in and out of your mouth and nose. That is all nature.
Today I woke up and everything was filled with fog. I jogged to the lake nearby and I could barely see the difference between the lake and the sky. Everything was white. The only indication of the water were the slight ripples 2 meters from my feet. I observed how the black shapes of the birds came into view through the white and disappeared again in the fog. I saw the tiny fish peek their heads for one second out of the water, creating more tiny ripples and disappearing again to leave the scenery again in its whiteness. As I jogged back through the forest, I observed how the heat throughout my body became greater and greater. How I went to feeling so cold so gradually being completely warm, through the movement of my ligaments. This is one of my favorite things to observe when the weather gets cold: how I am able to create my own heat through movement.
Observing is available to us every living second. And when we observe, there is suddenly silence, and through this silence we are able to remain in the present moment.