At a 40-foot diameter, this massive horticultural timepiece greets thousands of visitors to the Niagara Falls Botanical Gardens annually, and no two visits in the year may be the same. Its bedding of 16,000 flowers is rotated out twice a year to showcase spectacular blooms. Lucky guests can even view the mechanisms powering the clock if the tower is open. Its original builder, Ontario Hydro, has powered this clock since 1950.