In spite of its association with the Rocky Mountains, Denver is actually built on a high plain and is one of the flattest cities in the United States. The two outstanding features of Denver's environment are its proximity to the mountains and its altitude. The most prominent peak visible from the city is Mount Evans, at 4,346 meters (14,260 feet). On clear days, Pike's Peak (97 kilometers/60 miles to the south) and Long's Peak (80 kilometers/50 miles northwest) can also be seen.
Denver's altitude, which averages 1.6 kilometers (one mile) above sea level, ensures its residents a low level of air pollution and skies that appear bluer (also due to lower levels of water vapor). Water in Denver boils at 112°C (202°F) rather than the standard 118°C (212°F), making a challenge out of cooking, or even brewing a good cup of coffee. On the other hand, the altitude lends itself to beer brewing, for which the city is famous.
Denver also receives nearly 25 percent more ultraviolet radiation than cities at sea level, making it important for its residents to receive adequate protection from the sun.