The torii gate⛩️ of Ise Shrine, (one of) the most important Shinto shrines in Japan, enshrines Amaterasu-Omikami, the sun goddess and chief deity of Japan.

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I said "one of" because I think there are a variety of opinions, but if you ask Japanese people, "Which shrine is the most important to the Japanese people?", I'm sure that over 90% of people would answer "Ise Grand Shrine.
“Chief deity” is the simplest and easiest to understand expression.