It takes a certain amount of sacrifice and discomfort to visit El Tatio. For one thing, you will sacrifice sleep, as all tours leave very early in the morning. The steam from the geysers is most active and visible at dawn, so you need to be there before sunrise. You must also be prepared to be very cold and to cope with altitude; the geyser field is at 4,200 metres above sea level. So is it worth it? Oh yes!
These hexagonal pillars look more man-made than natural. They are quite regular in size, creating the impression that they were somehow manufactured. In a sense they were, but by nature rather than man.