From Atlas Obscura:
In 1804, Napoleon, then in charge of northern Italy, passed the Edict of Saint-Cloud. On the heels of the 1835 cholera epidemic, as churches began to move stacked bodies out of overburdened catacombs and new burials took up the remaining urban space, plans were finally made for a monumental cemetery on the outskirts of town.
Designed by the famous Genovese architect Carlo Barabino in a Neo-Classical style, the Staglieno Cemetery (Cimitero Monumentale di Staglieno) opened in 1851. A compromise between the formality of the traditional orderly camposanto layout and the newly fashionable wilderness style of boschetto irregulare, seen in Père Lachaise in Paris, the grounds included cloisters, garden paths, and a reproduction of the famous Pantheon in Rome. The new cemetery quickly became the fashionable death option, and increasingly was a showcase for world-class sculpture.