I believe this was part of the 150 acre John Forney Farm. The buildings are now gone, but were located a bit farther north or to the right of the border of the photo (near where the 17th PA Cavalry Monument stands today). The buildings were razed before the dedication of the Peace Light, apparently because they were in deplorable condition.
View attachment 392183
View attachment 392184
The heavy casualties in this area occurred later on the first day, long after the 9th NY Cavalry (which did much of its fighting north and east of the location depicted here) had departed. This appears to be the area of the southern or right end of the attack formation of Brigadier General Alfred Iverson's Brigade. One report of the total casualties for the brigade is 903 out of 1,384 (65%).