Heads up: some links here are affiliate links. Book or buy through them and we may earn a small commission at no extra cost to you. We only point you to things we would actually use. Most visitors watch a ship pass through the Miraflores Locks without understanding why the canal needs locks at all, or what the yellow electric locomotives running alongside the ship are actually doing. This is the mechanics and the history behind the spectacle; for where to go and how to plan an actual visit, see our separate guide to visiting the Panama Canal .