Maple Walnut Brittle

In heavy bottomed saucepan, over medium heat, stir together syrup, sugar, butter, and water until melted and creamy. Continue to gently boil and do not stir until candy thermometer reaches 300 degrees F "hard crack". Immediately stir in walnuts and carefully pour hot mixture onto an ungreased cookie sheet and spread out to a thin layer with a wooden spoon. Cool completely. Break into large pieces and store in an airtight container.