The following blog post was written by Carlos Caso-Rosendi, who is one of the most knowledgeable writers out there on the subject of Catholic eschatology:
TRANSLATOR’S NOTE: The following is an account of the events surrounding an alleged apparition of Our Blessed Mother in Puerto Rico. Should these events be approved by the Church as worthy of belief, that would be the only continuous apparition of Our Lady ever, lasting from 1899 until 1909, beginning shortly after the end of the Spanish American War of 1898. The events described below took place in an isolated mountainous area in Puerto Rico at a time when communications to and from the island were few. Carlos Caso-Rosendi
The Holy Mountain (Santa Montaña), altitude: 2,226 ft above sea level, in the Espino neighborhood of the Municipality of San Lorenzo, is a locality near where the municipalities of San Lorenzo, Patillas and Cayey meet. This mountainous region is located within a natural reserve—the Carite Forest—which consists of about 6,400 acres of tropical rain forest that are part of the Sierra of Cayey. As of 1954 and by mandate of the government of Puerto Rico—for all official purposes, including cartography—Cerro Las Peñas (The Stones Hill) was named Cerro de Nuestra Madre (Our Mother’s Hill).
The Our Lady of Mt Carmel Diocesan Sanctuary, is located at the top of La Santa Montaña in Puerto Rico. It was built and dedicated in 1985 by the bishop emeritus of the Diocese of Caguas, Monsignor Enrique Hernández Rivera. The story of La Santa Montaña begins on August 8, 1899, when the atmospheric phenomenon known as Hurricane San Ciriaco left the island after crossing it diagonally leaving 3,369 dead and hundreds of thousands homeless. The losses were estimated by the government at the time in US$35.8 million.