Alloa Tower is one of the largest towerhouses in Scotland and was built in the mid-14th century for the Erskine family, Earls of Mar. A mansion was added to the side of the tower in 1680. The tower was renovated by the 6th Earl in the early 1700's with a Charter Room, great staircase, gallery and entrance added. The mansion burnt down in 1800 then later rebuilt, but fell to ruin and was eventually pulled down in 1960. The tower was derelict until 1988 when it was restored. During restoration work a well was discovered within the walls of the 1st floor, which was cleared and fully revealed. It has been given a date of mid 14th century.
A number of masons' marks were noted in the well by Peter Leeming during a visit in 2010, who photographed them and sent on the information to the Project. He also noted a number of other marks but was unable to photograph them or identify their shape clearly, due to the narrowness and depth of the well. Two marks of two different masons were recorded.