The tallest freestanding structure in the world, at 1,815 ft and 5 inches high, is worth a visit despite the steep fee, if the weather is clear. There are multiple observation decks -- with glass floors, a revolving restaurant, and the world's highest public observation gallery. All levels offer spectacular panoramic views. On clear days you can see the mist rising from Niagara Falls to the south. Peak visiting hours are 11-4. COST: Observation levels $15.99; concourse attractions and Sky Pod at an additional cost. Sun.-Thurs. 10 AM-10 PM, Fri.-Sat. 10 AM-11 PM; hrs for attractions vary so call ahead.