Given the fact that Cocora Valley is both high up (about 2300m) and hundreds of miles from the ocean, the existence of these famous wax palms doesn't make a lot of scientific sense. Nowhere else in the world do palm trees grow at such a high altitude, to say nothing of their incredible, largely unnecessary, height. The best explanation I've received is that this area, long long ago, used to be a sea-level jungle. Over millions of years the mountains and hill raised and much of that sea-level jungle vegetation was replaced by competing fauna. However, these durable palm trees survived and are still evolutionary predisposed to 'thinking' they need to compete for sunlight in a jungle environment, i.e. grow very tall. That kind of height is no longer required for survival, obviously, but it does result in a surreal landscape. You'll be walking along an empty field only to encounter a lone, 180 foot tall palm tree, surrounded by nothing but grass for hundreds of yards in any direction - quite a sight!