A vintage postcard showing the front campus of Miskatonic University. The lack of paved crosswalks would date it to sometime before 1924. Click through for the high resolution version.
This is based on a postcard of Brown University's front campus dating to around 1910. I believe the spot where this picture was taken is in front of the John Hay library, just north of the intersection of Prospect and College Streets. I'm guesstimating it's about 10 meters south of where the H.P. Lovecraft Memorial is located today.