Pakistan is 35th Biggest country in the world having an area of 796,096Km2.
1) Abotabad:
According to area abotabad is on 1st number while we talk about area,its area is 18,013Km2.
2) Attock:
Attock is 2nd biggest city of Pakistan with an area of 6,857 Km2.
3) Sheikhupura:
Sheikhupra has an area of 5,960Km2 and have a place of number 3rd.
4) Sargodha:
Population wise Sargodha is not a big city but according to its area it has 4th place with area of 5,854Km2.
5) Swat District:
Sawat is the fifth biggest city according to its area 5,337Km2.
Note: Above figures of area are taken from latest record of google.