There is a small hospital that wanted to understand why some patients fared better than others. Looking back at the records of those who stayed in rooms whose windows faced a brick wall compared with looking out on a courtyard of trees, the distinction was clear. The former group complained more, experienced greater pain, and took longer to heal. Their nurses made four times as many notes of negative progress, and they required additional meds. Two contrasting outcomes, with nothing but trees to divide them.  

Recently I watched a series of documentaries about exotic hotels. One was perched high in the cloud cover of a forest in Ecuador. Another looks out on the rocky coast of Newfoundland. A third ensconces travelers in the domain of local giraffes. The guests described what drew them at both great expense and inconvenience to these havens of sanctuary. Being immersed in nature replenishes them. Hiking along jungle paths, uncovering wildlife, and feeling the sharp ocean winds cleared their minds. Being inches away from stately animals was invigorating.

The belief is that natural surroundings offer a restorative environment, labeled eustress, as opposed to distress. Even two hours a week in a green space left newly diagnosed cancer patients better equipped to handle mental challenges. Being surrounded by woods lowered both their blood pressure and levels of cortisol.