This is a jija ( Shinto shurine ) to enshrine Shinto's deity.
Shinto is an indigenous faith of the Japanese. It is a way of life and a way of thinking that had been an integral part of Japanese culture since ancient times.
A Shinto shrine is a holy and sacred place. There are certain and traditional rules you should follow to worship when visiting those ritual places. And it would be appreciated if you follow the rules as well, as the saying goes, "when in Rome, do as the Romans do."