Line a large baking sheet with a silicone mat or buttered parchment paper. In a large saucepan, combine the sugar, water and corn syrup and cook over moderate heat, stirring, until the sugar is dissolved. Using a moistened pastry brush, brush down any crystals from the side of the pan. Cook the syrup until it registers 235° to 240º on a candy thermometer. Add the almonds and salt and cook, stirring occasionally, until a deep-amber caramel forms and the thermometer registers 300°, about 5 minutes longer.