The tower is 54 feet high and it is circular. It is 42½ feet in diameter with a cone-shaped roof. There is a spiral staircase within the thick walls - these are 10 feet wide at the base, going down to 7 feet at the top. It was part of the old city walls of Waterford which were in a triangle formed by three structures — Turgesius Tower on Barronstrand Street, St. Martins Castle on Lady Lane, and Reginald’s Tower at the Quay and the Mall. It was on the high ground between St. John's River on the southeast (since drained, and now known as the Mall) and the River Suir to the north. It is also very close to the historic French Church. It is also known as the Ring Tower. It was one of seventeen towers which circled the city of Waterford in medieval times. Today, it is the largest of the six surviving towers, which are considered the best examples of medieval urban defence in Ireland. The other surviving towers are the Watch Tower, Double Tower, French Tower, Semi-Lunar Tower and Beach Tower.