Those two hours don't have to be from one visit, it can be spread over the week, and you'll still get similar health benefits, say researchers from the University of Exeter who looked at the health and lifestyles of around 20,000 people.
Time spent in woodlands, town parks, country parks or beaches will all reap rewards, provided you do so for 120 minutes or more each week. That seems to be the threshold, and people who reported spending less time than that in nature each week also reported lower levels of psychological wellbeing.
Most of the participants found their natural setting less than two miles from their home, and even local urban greenspaces seem to work, says researcher Dr Matt White. "Two hours a week is hopefully a realistic target for many people, especially as it can be spread over an entire week," he added.
The idea of nature having therapeutic value has been adopted by the Japanese, who call it shinrin-yoku, or Forest Bathing. It's been proven to reduce stress and anxiety, the researchers say.