The west wing and crypts of this medieval Romanesque cruciform structure date from the 11th century, and there's evidence of an earlier church and even a pagan place of worship on the site. But the focus for most visitors is the side chapel containing the statue of Our Lady Star of the Sea. The richly robed statue, fronted by a blaze of candles, is credited with many miracles, even during long years when it was hidden away because of religious persecution. In the early 1600s, as many as 20,000 pilgrims came to worship at the shrine every Easter Monday. When the Calvinists took power in 1632, the statue went into hiding. Legend has it that in 1699 Our Lady herself established Maastricht's "prayer route" by stepping down from her pedestal and leading a devout parishioner through the muddy streets, and that the morning after the miraculous walk there was indeed mud on the hem of her robe! The church treasury contains a rich collection of tapestries, reliquaries, church silver, and other religious objects.