Combine sugar, butter, corn syrup, and water in a large saucepan.Heat on med. Heat until butter is melted. Increase heat and bring to a boil and boil for approx. 13 minutes or until 280-290 on a candy thermometer, stirring constantly. Pour into a buttered 15x10 pan which has been sprinkled with the almonds. Let cool for 5 minutes. Break chocolate bar into squares and place on top of toffee. When melted, spread evenly. Cool completely. Break into pieces.