Battery Tynes - Credit: Wikimedia Commons
Battery Tynes is a historic artillery battery located at James Island, Charleston, South Carolina. It was built in 1863, and designed to protect the upper Stono River and the bridge from James Island to Johns Island, South Carolina. The earthen redoubt measures approximately 320 feet long and 180 feet deep. It has a 10–20 foot high parapet wall and a 15 feet high powder magazine. Read more on Wikipedia
Source: en.wikipedia.org