Alloa Tower in Alloa in central Scotland is the surviving part of the medieval residence of the Clan Erskine family, the Earls of Mar. An architect which was involved in the Alloa Tower was John Melvin. Dating from the 14th century, and 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 is now administered by National Trust for Scotland.