Jesus was accompanied by his disciples Peter, James, and John on the Mount of Transfiguration.
Moses and Elijah
The word is Transfiguration. None of the accounts in Bible identified the mountain where the Transfiguration occurred
It is believed to be the traditional place of the Transfiguration of Jesus in front of Peter, James, and his brother John.
On the Mount of Transfiguration, Jesus was "transfigured," meaning that he was seen by the Apostles Peter, James and John in his glorified form, bright as the sun in blazingly white clothes. In this form, he spoke with Moses and Elijah, who also appeared there with Jesus. See Luke 9:28-36.
Peter wanted to build three tents on the Mount of Transfiguration because he wanted to honor Jesus, Moses, and Elijah by creating a place for them to stay.
To the garden of Gethsemene and the mount of transfiguration.
Because Peter, James and John had witnessed the transfiguration at the mount and Jesus wanted to keep it a secret.
Matthew 17:1 or Mark 9:2
Church of the Holy Transfiguration of Christ-on-the-Mount was created in 1891.
Jesus and Moses were not contemporaries, although Moses did appear with Elijah to Jesus on the Mount of Transfiguration. Jesus did give respect and credibility to Moses' writings and referred to the fact that Moses spoke about Him in His writings.
Jesus took a few disciples to a mountain call Mount of Transfiguration. Where the two prophets of old prophet Elijah and prophet Moses were seen by the disciples.
The Transfiguration of Jesus is recorded in the Synoptic Gospels (Matthew 17:1-9, Mark 9:2-8, Luke 9:28-36), which, as you mentioned in your question, involved the appearance of Elijah and Moses with Jesus. As for where it occured, Christian tradition says it took place on Mount Tabor. More recent scholars suggest that the "high mountain" mentioned in the passage could have been Mount Hermon or Mount Nebo.