The physical beauty of a place is part of the equation. But (for me at least) the weather at the time of visit, the sounds, and the smells all play strong roles in my appreciation of a location. I recall visiting the Porcupine Mountains SP (MI) west unit and walking along the riverbank on a sunny 70 degree day. Smelling the trees and plants, hearing the water splashing along and the birds in the trees, and seeing the water tumbling over sculpted ledges and cascading over falls and kids playing at water's edge all produced a sensory delight that stays with me to this day.