The Blessed Virgin Mary appeared to a small group of persecuted Catholics living their faith in a jungle in Vietnam. They suffered privations, dangers, and illnesses. They recited the rosary daily and on one evening, the Blessed Mother appeared to them telling them that she fully understood their hardships. She told them, among other things, to gather the leaves from a plant that grew by them and boil their water with them to purify it. She also providently told them “From this day on prayers said on this spot will be heard and answered.” That was in 1798 and pilgrims have had answered prayers since.