Located in the central nave of the church of St. Mark, the "Arca” is a very modern structure made of glass and steel. This innovative parallelepiped structure has now become one of the symbols of the city, as well as a symbol of the desire and ability to link the ancient with the contemporary: the glass vaults of the Arca allow guests to admire the majestic medieval vaults of St. Mark. In turn, the ex-church is once again displaying its marvellous 15th century frescoes to Vercelli residents and tourists. The frescoes were hidden until young restorers from the Centro Conservazione e Restauro "La Venaria Reale” uncovered them. The building is a venue for events and exhibitions: two of the most important were: "Il Rinascimento di Gaudenzio Ferrari”, held in collaboration with the Guggenheim Foundation; and the exhibition dedicated to the Magna Charta and the 800 years of the Abbey of St. Andrew.