The Eisenhower interstate system requires that one-mile in every five must be straight. These straight sections are usable as airstrips and in times of war or other emergencies. The water of Angel Falls (the World's highest) in Venezuela drops 3,212 feet (979 meters). They are 15 times higher than Niagara Falls. Theatres in Glendale, California can show horror films only on Monday, Tuesday, or Wednesday.