A munro is a Scottish mountain that is over 3,000 feet (914.4 m) and is listed on the Scottish Mountaineering Club (SMC) official list of Munros.
However, it's not quite as simple as that. According to comedian Ed Byrne, a self-confessed Munro-bagger: "the exact definition of a Munro is quite fluid. Not every separate peak is a Munro. There has to be a certain amount of distance, height loss and regain of height for a particular summit to be considered a Munro in its own right, rather than a subsidiary summit or ‘top’ of the adjacent Munro. Worst of all, these criteria are not hard and fast rules. That has led to much controversy, discussion and revision of the list over the years."
In total, according to SMC's list, there are 282 Munros. The highest Munro - and therefore the highest mountain in the UK - is Ben Nevis at 4,411 ft (1,345 m).
Munros are named after Sir Hugh Munro, a keen mountaineer who was the first to list the mountains in 1891.
What is Munro bagging?
Munro bagging is when someone makes it their mission to climb as many Munros as they can and tick them off the list. Once you have bagged all the Munros, you may call yourself a Munroist. You can also let the Scottish Mountaineering Club know about your triumph, as they keep a record of compleators.
The fastest compleator is Donnie Campbell, who took just 31 days, 23 hours and 2 minutes to bag all the Munros. We're not sure how much sleep he got!
Main image: Munro Ben Lomond view from Loch Lomond @ Getty Images