The book of Mormon at the Fayette Chapel at the Peter Whitmer farm in upper New York state.
Peter Whitmer farm is the location where Mormonism was organized. The mormon.org site describes the location as follows:
...on 6 April 1830, The Church of Jesus Christ of Latter-day Saints was formally organized with six members.
Members of the Whitmer family did much to further the budding Church. They took in the Prophet Joseph Smith Jr. and his wife Emma for a period of time and allowed Joseph and Oliver Cowdery to work on the translation of the Book of Mormon in their home. Joseph also received revelations comprising 20 sections of the Doctrine and Covenants, and some of the first priesthood ordinances were performed in or near this home.