Passing through the streets of Florence in the rain, Mowenwei's married Women's Prison Hotel (Fig. 1) and Dante's former residence (Fig. 23) finally returned to St. Cross Square. The square in front of the Church of the Holy Cross is a larger square in Florence, so it has been the place for festivals, performances and competitions since the Renaissance. On one side of the square is a coloured wall building (Fig. 8). It is the home of the 18K gold creator. The windows on the wall are interesting. The family's gold shop is still in operation (Fig. 9). It features four-color gold jewelry - platinum, gold, rose gold and black gold. I can't help losing a four-color gold ring. Its gold content is only 75 [%]. It's really small.