First of all, Zaragoza is NW of Spain, middle way between Madrid and Barcelona. Main Campus is at Zaragoza city, but some sections are scattered around Aragon, within a range of 150 Km. So be sure where you want to go.
Zaragoza sits on a strategical location (well, it was in Caesar August times...), so there are a lot of methods to reach the town, ask your travel agency. If you are adventourous, you could try to reach Paris with the Concorde, then Paris-Irun on TGV, and then Irun-Pamplona-Zaragoza on fast train.
The University main campus is easy to find, it is near Plaza San Francisco, in the middle-south part of the City. You could need to use a map of Zaragoza to find it. We have also some other formats on our gopher.
The Theoretical Physics Department (Fisica Teorica, in Spanish) is in the Sciences Faculty (Facultad de Ciencias). You can locate it in this map of the Zaragoza University main campus. It is the one H-shaped, west of the pool, (beware our map is oriented with West in the top!), and East from the stadium. More data on the University is at the central gopher.
PS: If you are planning WWW maps, look better for html+ fig directive. You can find an example here