The address of the School of Communication, the central venue, is:
Facultad de Ciencias de la Información
Universidad Complutense de Madrid
Avenida Complutense s/n - 28040 Madrid – Spain
It is only 2 minutes walking from the metro station "Ciudad Universitaria" (Line 6 - the grey one), as you can see in the video on how to arrive.
In Google Maps, you can easily find this location at https://www.google.com/maps and calculate time and ways to reach the venue.
On the map below, the School of Communication (Facultad de Ciencias de la Información) can be identified by the red spot, while the metro stations can be identified by the logo.