The Assumption of Mary
The Assumption of Mary, the Mother of God, is a Catholic Church feast day in August. It has been on August 15th for almost 1500 years. But earlier, historical evidence shows it moving between January and August. Why these months is another story that is not known to us.
We do know that there are two tombs of Mary. One in Jerusalem and the other in Ephesus. Jerusalem is an obvious location, and Ephesus is because Mary is said to have been under the care of the Apostle John in her later years, and John's tomb is in Ephesus. At either holy site when you visit, the guides will respectively deny the validity of the other tomb. But God's ways are not our ways, and so we have two tombs of Mary.
So what is the Assumption of Mary? Mary is the Mother of God, Theotokos in Greek. She has been referred to as the new Ark of the Covenant. This was the Holy of Holys to the ancient Jews. Mary carried baby Jesus for nine months; her body is thus holy, and God did not want her body to experience corruption and decay after death. God had already set the precedent in the Old Testament when He assumed Elijah in to Heaven in a whirl wind of fire. He can certainly do that for the mother of His only begotten Son! And so, after Mary died, or as she was dying (we really don't know), God took her body up to Heaven.
Most of us have heard of the Pope's ability to speak infallibly, that is without error. He has only spoken twice like this in the whole history of the Catholic Church. It isn't something that happens every day or even every year. Both times refer to Marian Feast Days, the Assumption and the Immaculate Conception. Both of these Marian beliefs have been in the Church's Tradition forever, but they had never been formally expressed. It was time to make official Church doctrine on these two subjects.