I bet you already know,that once you setup Apache,anyone can access your /var/www folder,just by typing your ip address in firefox’s navigation bar.
But what happens when your ISP (Internet Service Provider) blocks port 80?
(Port 80 is the default port http requests use)

First of all, check whether your ISP is blocking your port here.
(You need to have installed and configured already on port 80, for this to work)

@Complete Story