Meaning of Symbols/Icons on Amgen-ToC Stage Maps
RED Circle with numbers 1-5 : Climbs with range of difficulty

RED Circle with numbers "HC" : Hors catégorie or Above Category

Blue Circle with knife/fork : Feed Zone where you grab your musette

Green Circle with white "S" : Sprint Zone

Blue Circle with "km 0" : Just means no break-away is allowed before this point. In essence "the race starts here"