GREC 2013 is taking place at Lehigh University. Lehigh University, Bethlehem, PA is a 1h30 drive west from New York city, and a 1h30 drive north of Philadelphia, as shown on the map here.

The exact location of the conference room on campus is:

Lewis Lab 270
Sherman Fairchild Center
16 Memorial Walk East

(that is building 16 on this map)

Getting to Lehigh University

Venue Pictures

These pictures were taken on Aug. 21, 2012, on the exact same time of the year GREC will be taking place in 2013, and show the Lehigh University campus in the direct vicinity of the workshop location. 
Credits: D. Lopresti