Perimeter Center is a commercial edge city and business district surrounding Perimeter Mall. Although about 40% of Perimeter Center, including the mall, is located in Dunwoody, the western 60%, including most of the area's office towers, are located in Sandy Springs. Pill Hill is located in the Sandy Springs section of Perimeter Center, and is the largest medical center in Georgia. It includes Northside Hospital, St. Joseph's Hospital, and Children's Healthcare of Atlanta. More than 40% of the hospital beds in the metro area are located within Sandy Springs. Landmarks include Hammond Park and the Sandy Springs and Medical Center MARTA stations.