http://hacktowns3sba2xavxecm23aoocvzciaxirh3vekg2ovzdjgjxedfvqd.onion/misc.php?action=ACTII-5
By default nmap will skip any hosts that don ' t reply to a ICMP echo request and we don ' t want to miss anything fun like a forgotten webserver displaying home directory contents or something stupid left open , unattended , and insecure. So , ensuring that when -Pn is added nmap assumes the host is alive and scans it accordingly.