It now houses the Civic Museum of Ancient Art (Museo Civico di Arte Antica) beside a splendid ceremonial staircase, also designed by Juvarra.
Today, it is home to the Civic Museum of Ancient Art. 
mnli hypothesis: Today, it is home to the Civic Museum of Ancient Art.  premise: It now houses the Civic Museum of Ancient Art (Museo Civico di Arte Antica) beside a splendid ceremonial staircase, also designed by Juvarra.