Found this English site on the mountain we’ll be visiting, Tateyama. Here’s a description from the site:

Along with Mt. Fuji and Mt. Hakusan, Tateyama is one of Japan’s Three Sacred Mountains and has been worshiped since ancient times. Tateyama Range is a spectacular and solemn display of peaks, soaring to an altitude of 3,000 meters. The variety of its topography creates a beauty of nature which has long been the love of many alpinists. With the completion of the Tateyama Kurobe Alpine Route, linking Toyama and Nagano Prefectures, Tateyama’s heights have become accessible to us as an international alpine sightseeing area. Tateyama, as nature, is both gentle and severe. Its appeal lasts from season to season, year to year, and it allows us an impression and peace of mind.