It is believed that Timbuktu was founded by Tuareg nomads during the year 1100 AD. The name of 'Timbuktu' was derived from.....a well, owned by an old Tuareg woman. The woman's name was Buktu and 'tin' means well, hence Timbuktu can literally mean 'the well of Buktu'. Below is a photo of the famous well. (I am skeptical about the dried up hole having such an important role in Timbuktu's history, but there is no harm accepting the story at face value I guess.)
Where it all began..with a well
Source: Economist.com