the cathedral's appeal doesn't end in the sanctuary - in fact underneath the main building, in the basement, is the museum of sacred art. among the relics on display are the basin used to baptize the princes of the royal family, the throne of dom pedro ii and the golden rose given to princess isabel by pope leo xiii, in celebration of the signing of the golden law (Lei Áurea), which abolished slavery in brazil in 1888). 

paintings, sculptures, furniture, porcelain, silverware and jewels are also displayed here, many dating to brazil's days as an empire - or even further back, to the colonial era.