It was always a heated debate between scholars on which cities are the oldest in the world.
10,000 years ago, some human tribes began settling in one permanent location and transformed their nomadic way of life to a more sedentary one. While there is a consensus on the city of Jericho, Palestine to be oldest known human settlement that is inhabited untill our days, 3 Lebanese cities can also be dated back to this early era of human life development. Beirut, Sidon (Saida) & Byblos (Jbeil).
For thousand of years these cities flourished & gained a status of main attractions of the Old World.
It goes without saying that their locations on a strategic beach-shore at a time when populations of the East Mediterranean basin were beginning to bond and create commercial relations between them was of an important deal for their strive.
At one time Byblos took the lead and invented what was going to be one major human achievement of all times. The Phoenician alphabet. The base of all Western alphabets used these days.
More info on the oldest cities in the world here: http://arabicpages.com.au/article/the-10-oldest-cities-in-the-world.html