Once you find Columbia, you will need to navigate around campus. The building housing the Physics Department is named Pupin Hall. It is located in the northwest corner of the campus (in section D of the campus map). Although Pupin Hall is situated on the corner of Broadway and West 120th Street, it is usually not possible to enter the building from there (it has key/card access only). So be sure to approach the building from the south side (the campus side). That will bring you to the main (5th floor) entrance (yes, the 5th floor). The Physics Department office is on the 7th floor. Once you are there, they should be able to direct you to where you need to go. If you get lost, call the office at 212-854-3366 or if you are calling from a campus phone just dial 4-3366.