In The Church of Jesus Christ of Latter-day Saints (LDS Church), a temple is a building dedicated to be a House of the Lord. Temples are considered by church members to be the most sacred structures on earth. Upon completion, temples are usually open to the public for a short period of time (an "open house"). During the open house, the church conducts tours of the temple with missionaries and members from the local area serving as tour guides, and all rooms of the temple are open to the public. The temple is then dedicated as a "House of the Lord", after which only members who are deemed worthy are permitted entrance. They are not churches or meetinghouses designated for public weekly worship services, but rather are places of worship open only to the faithful where certain rites of the church must be performed. There are 155 operating temples (which includes 3 previously dedicated, but closed for renovation), 14 under construction, and 13 announced (not yet under construction). At present, there are temples in many U.S. states, as well as in many countries across the world. Several temples are at historical sites of the LDS Church, such as Nauvoo, Illinois and Palmyra, New York. The importance of temples is often emphasized in weekly meetings, and regular participation in "temple work" is strongly encouraged for all Latter-day Saints (LDS).
Within temples, members of the church make covenants, receive instructions, and perform sacred ceremonies and ordinances, such as baptism for the dead, washing and anointing (or "initiatory" ordinances), the endowment, and eternal marriage sealings. Ordinances are a vital part of the theology of the church, which teaches that they were practiced by the Lord's covenant people in all dispensations. Additionally, members consider the temple a place to commune with God, seek God's aid, understand the will of God, and receive personal revelation.