The Shinto religion is strongly connected to nature, and in the old times, before the shrines we know today, the kami were venerated in the nature, in places indicated by trees or rocks. These were called yorishiro, objects capable of attracting kami.
The tree was often selected in a silent forest area, and simply marked with a shimenawa. Even today, many Shinto shrines are located deep in the forest, their presence marked with torii gates and sometimes with lanterns, like in this photo taken near the Hakone Shrine.
Yesterday’s Japan Photo: