Munros are 3000-ft mountains in Scotland that were surveyed and tabulated in 1891 by Sir Hugh Munro. Before Munro published his tables it was not known how many 3000-ft mountains there were in Scotland. It was estimated by some that there were about thirty, whereas the current Munro's tables list 277. The list is revised occasionally -- to the dismay of purists -- based on contemporary surveying techniques.

One basic problem was to define what a separate mountain is. Munro was a bit arbitrary in his selection, but generally required that the summit, or "top", of a separate mountain has to be at least one-quarter mile from any other top, and there must be a vertical drop of at least 500-ft between tops. Mountains generally meeting these criteria have come to be called "Munros".

It has become a popular challenge to "do" all the Munros. This is referred to as "Munro Bagging", which is carried out with a degree of fanaticism by a large number of hikers and "hill walkers", who might otherwise simply enjoy climbing the mountains for the exercise and the views from their summits. Munro himself never climbed all the mountains on his original list. The first person to do this -- the first "Munroist" -- was A.E. Robertson, who completed them in 1901. The next Munroist did not complete the challenge until 1923. In recent years, however, Munroists are being added at the rate of, probably, more than 50 per year.