An attraction is any object, person, place, or concept that draws people either geographically or through remote electronic means so that they might have an experience. The experience can be recreational, spiritual, or otherwise.
Ultimately the market — not tourism experts or magazines — decide what is an attraction among its much wider resource class. If people spend time and money to experience a particular resource, then that resource is also an attraction.
This category includes mountains, gorges, big rocks, rock formations, caves, rivers, water bodies, scenic views, overlooks of forests (when the attraction is merely seeing and not interacting more directly with the forest), unusual cloud formations, unusual meteorological conditions (high velocity or unusual wind behavior, light hitting or passing through geological formations in strange ways), thermal waters, volcanic activity, or even unusual celestial events such as the Northern Lights, Perseid Meteor Showers, or exceptionally clear night views for star-gazing.