The title of Canto 16 is "Violent against Nature." The three men are in hell, it seems, for sodomy. Their punishment is to clutch each other as in a dance, or like wrestlers, and wheel around again and again for eternity on what seems to be scorching hot sand, surrounded by fire. Dante would have greeted them more warmly if doing so would not put him at risk of being burned. The men were very powerful in life, where they were members of the Guelf political faction in Florence. Dante clearly admires them a great deal, in fact probably as much as anyone else in Hell except for Vergil or Ulysses. One of the men, it is pointed out earlier, was driven to his vice by his wife.