In their book on LDS historical sites in Hawaii titled "Sacred and Historical Places: Hawaii," Mary Jane Woodger, Riley Moffat and Fred Woods discuss a site on the island of Oahu once known as King’s Falls. Presently, it is called Kapena Falls.
Stream below King's Falls, now Kapena Falls, Oahu, Hawaii. | Kenneth Mays
It was there that early missionaries of The Church of Jesus Christ of Latter-day Saints offered up a prayer of dedication on Dec. 13, 1850. There were 10 missionaries in the group. There in the pool at the bottom of the falls, those missionaries had their first chance to bathe in more than a month. The authors note that the missionaries climbed to a site where they could overlook Honolulu, about 1,000 feet below.
The authors cite a journal account of missionary William Farrer, which recorded that on that occasion, those missionaries each “carried a stone and all built an alter (sic); we then sung a Hymn and each one expressed his feelings in regard to the mission we are now on. Brother Clark then offered up a prayer unto the Lord that he would open the way that we might be enabled go preach the gospel on these islands” (see "Sacred and Historical Places: Hawaii").
At sunset, the missionaries descended the mountain full of joy, spiritually motivated to engage in the work they had embarked on.
Accounts say that the altar the missionaries built was about 500 feet above the falls. Later attempts to find the exact site of the altar were unsuccessful. Today, a short trail to the site is accessed from inside a cemetery several miles from downtown Honolulu.