Österreichisches Forschungsinstitut für Artificial Intelligence
Freyung 6/6, A-1010 Vienna, Austria

The closest subway station is Schottentor (U2). Within walking distance are Herrengasse (U3) and Stephansplatz (U1, U3).

Usefull links for getting around Vienna:
-- Map Service
-- Public Transportation Schedules
-- Turist Guide

The picture below shows how you can enter the inner courtyard of the Schottenstift (Monastery). You need to press the OeFAI button to open the iron gate. The OeFAI is located on the third floor. (Sorry, no elevators.)