National Shrine of the Assumption of the Blessed Virgin Mary. In 1806, Bishop John Carroll placed the cornerstone here, the Mother Church of Roman Catholicism. Museum housing artifacts dating from the 17th century, including the chasuble worn by Pope John Paul II at a public Mass at Camden Yards in 1995. M-F 7 am-4 pm, Sa 8:30 am till end of 5:30 pm Mass, Su 7 am till end of 4:30 pm Mass. Guided tours M-Sa 9 am, 11 am and 1 pm, Su noon. Gift shop open daily.