Pakistan does actually require a visa for a foreigner to visit the country. However, it is relatively easy to secure a Pakistani visa for a visitor. To secure a Pakistani visa you will need to visit your closest Pakistani consulate in order to file in an application get done with necessary documentation. It may be a bit tougher for Indian visitors as they would be required to abide by certain protocols if they happen to be visiting the country. However, you do need a visa in order to visit Pakistan.
