Wikitravel article: https://wikitravel.org/en/Mount_Koya

The main temple is Kongobuji, where Senju's panels are installed -  https://en.wikipedia.org/wiki/Kong%C5%8Dbu-ji

Senju's coffee table book about his works at Kongobuji temple - https://www.amazon.com/Koyasan-Senjus-Works-Years-After/dp/1649800622