Shattered Hoof Ridge was the site of a major battle during the war, and the place where Big Macintosh was killed.
During the War
Shattered Hoof Ridge, as the name implies, is a barren, rocky portion of Equestria near the Zebra border full of deep crags and ravines. At some point near the early to middle years of the Ministries the Zebras sent word to Canterlot that they were willing to negotiate a peace agreement if the Princess would come to Shatter Hoof Ridge to discuss it. They had intended this as a trap to assassinate Princess Luna, those plans were foiled when Princess Celestia arrived in her sister's stead.
Despite the wrong target showing up for the ambush, the Zebras still tried to carry out the plan and kill Celestia. Only being stopped when Big Macintosh saw the Zebra taking the shot and jumped in front of The Princess, taking the bullet for her and sacrificing his life. This led to a battle taking place immediately. Many survivors of which, including Sargent Applesnack, were rotated off front line duties and to roles in the central regions of Equestria, such as patrolling Zebratown, to recover from the trauma.
Afterwards, the Shattered Hoof Re-Education Facility was named after the location, with many of the ponies found complicit in helping to set up the assassination plan incarcerated there.
One of the fifty Single Pony Project towers was erected here.
After the War
During the Enclave's Operation: Cauterize the SPP tower erected here was destroyed by Homage rigging a Star Blaster to explode in the control room at it's base as a trap for an Enclave squad sent to capture her.