Wow. An engineering marvel...began in 1903 and still operating today much as it was designed. You enter the locks at sea level and after three steps up, ships are raised 84 feet (that's a lot when you consider how much you're lifting) and drive across Gatun Lake. Gatun Lake was created by damming the Chagres River and the transit across the lake accounts for 40-ish of the 51 miles to transit the entire canal. There are two lanes, both bi-directional in each set of locks - and NO PUMPS. The entire system runs off gravity from the water held back in Gatun Lake. Quite an experience!