You probably already do this unconsciously. When you get that itchy feeling from being inside too long, or from being surrounded by concrete and steel buildings all day. That urge to take off your shoes and walk in the grass, or lay under a tree, or go for a hike with just yourself, your mind, and nature.
In Japanese, this is called Shinrin-Yoku (森林浴) or "Forest-Bathing." Simply defined, it is a trip to a forest, or really anywhere in nature, to just take in the calming quiet you can only find in such places. It is now a common stress-reliving practice among Japanese. They actually have 44+ certified Shinrin-Yoku national forests through the country.
While it may seem kind of hokey to say 'just talk a walk and calm down,' every study so far has demonstrated reductions in, stress, anger, anxiety, depression and sleeplessness amongst the subjects that have participated.
It's practiced all over the world - and here is a great introduction to it!