The construction of the current collegiate church kicked off in 1450 with the chancel, wrapping up around 1506. The transept followed, completed in 1527, and the nave took until 1621 to finish. This architectural gem, shaped like a Latin cross with 29 chapels hugging the main nave, transept, and chancel, stands as a significant piece of Wallonia’s heritage. It was the private sanctuary for the Saint Waltrude canonesses, who envisioned a grand 623-foot tower crowning the church's west face. The foundation stones for this tower were laid around 1549, but it remained unfinished, with construction finally halted between 1686 and 1687. Make sure to explore the Treasury: it houses one of Belgium's most stunning collections of religious jewelry. You'll find the reliquary of St. Waltrude, which includes "la châsse" containing her body and "le chef" with her head. The church also boasts some of the oldest stained-glass windows, particularly the five in the apse. These were crafted by a master glassblower from Mons and gifted by Emperor Maximilian of Austria in 1510-1511. Don't overlook the remarkable sculptures, like the 15th-century statue of St. Michael defeating Satan and the 16th-century depiction of St. Waltrude. And if you time your visit right, you might catch a glimpse of The Golden Coach: a wooden vehicle painted and gilded in Louis XVI style from 1780/1781, which takes the spotlight during the annual Procession of the Trinity, known as Doudou. Wandering through the church, you'll feel a sense of history and artistry blending seamlessly. The intricate details in every corner tell stories from the past, inviting you to imagine life centuries ago. The atmosphere inside is both serene and awe-inspiring, a perfect reflection of the church's rich heritage.