Preheat oven to 350°F. In heavy skillet over medium heat, cook sugar, stirring constantly until melted and caramel colored. Pour into 9-inch round layer cake pan, tilting to coat bottom of pan completely.
In medium bowl beat eggs, stir in water, sweetened condensed milk, vanilla, and salt. Pour into caramelized pan. Set in a large pan. (a broiler pan) and fill pan with 1 inch hot water.
Bake 55 to 60 minutes or until knife inserted near center comes out clean. Cool. Chill thoroughly. Loosen side of flan with knife. Invert onto serving plate with rim. Garnish as desired.