Tranquillity (also spelled tranquility) is the quality or state of being tranquil; that is, calm, serene, and worry-free. The word tranquillity appears in numerous texts ranging from the religious writings of Buddhism, where the term passaddhi refers to tranquillity of the body, thoughts and consciousness on the path to enlightenment, to an assortment of policy and planning guidance documents, where interpretation of the word is typically linked to engagement with the natural environment. It is also famously used in the Preamble to the US Constitution - "insure domestic Tranquility". History The word tranquility dates back to the 12th century in the Old French word tranquilite, meaning "peace" or "happiness", although the word's sense evolved in the late 14th century. However, the word still keeps its reference to the absence of disturbance and peacefulness. Benefits Psychological being in a tranquil or "restorative" environment allows individuals to take respite from the periods of sustained "directed attention" that characterise modern living. In developing their Attention Restoration Theory (ART), Kaplan and Kaplan proposed that recovery from cognitive overload could most effectively be achieved by engaging with natural restorative environments, that are away from daily distractions and have the extent and mystery that allows the imagination to wander, thereby enabling individuals to engage effortlessly with their surroundings. The theory works on the principle that the amount of reflection possible within such an environment depends upon the type of cognitive engagement, i.e. fascination; that the environment holds. "Soft fascination" is deemed to occur when there is enough interest in the surroundings to hold attention but not so much that it compromises the ability to reflect. In essence, soft fascination, which has been taken by Herzog and Pheasant as a reasonable term to describe tranquillity, provides a pleasing level of sensory input that involves no cognitive effort other than removing oneself from an overcrowded mental space. Enjoyment For many, the chance to experience tranquillity is what makes the countryside different from cities. In a survey by the United Kingdom Department for Environment, Food and Rural Affairs (DEFRA) 58% of people said that tranquillity was the most positive feature of the countryside. Health In contrast to "soft fascination", "directed attention" requires a significant amount of cognitive effort and it is known that prolonged periods of sustained mental activity can lead to directed attention fatigue. This condition has the potential to significantly affect performance and bring about negative emotions,