Alloa Tower is an early 14th century tower house that served as the medieval residence of the Erskine family, later Earls of Mar. Retaining its original timber roof and battlements, the tower is one of the earliest, and largest, of Scottish tower houses, with immensely thick walls.
It was originally built as part of a line of fortifications defending the north shore of the Firth of Forth. Several 19th century works, including Groome's Gazetteer, date the tower to the year 1223. Archaeological investigations from the early 1990s date the original fortified house to the early 14th century, where it had a cellar that sometimes served as a pit prison. By the mid-14th century it had been enlarged with a great hall and rose to three storeys in height, with the entrance on the first floor. In the 15th century it was further enlarged to four/five levels while retaining its first-floor access. Late in the 16th century ground-floor access was probably added.
John Erskine, 6th Earl of Mar built a very large mansion (Alloa House) in 1710 that incorporated the tower as its annexe; he made plans to remodel the tower's interior, but it is unclear what changes were actually made. The house burned down in 1800 and was rebuilt by George Angus in 1834–1838 for the 9th Earl. It was demolished sometime after 1868.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.