A precious piece of mosaic flooring from one of the ceremonial ships built by Emperor Caligula to host festivities on Lake Nemi on Friday is being sent back to Italy where it will be returned to Nemi's Naval museum, Culture Minister Dario Franceschini has announced. The square piece of marble flooring, decorated with a floral motif made of pieces of green and red porphyry, serpentine and molded glass, was discovered at an Italian collector's Park Avenue apartment in New York City.

The mosaic dates back to Caligula's reign, 37-41 A.D., and came from one of three ships built at the volcanic lake. The mosaic - along with other antiquities including two vases, bronzes, coins and manuscripts - were retrieved thanks to an investigation carried out by the special art unit of the Carabinieri police led by Fabrizio Parrulli and US authorities, Franceschini said.