Maiden Tower is 28 metres high on its northern side and 31 metres high on its southern side. The walls are 5 metres thick. In appearance the Tower is cylindrical in form with a supporting wall of almost the same height. The eight storeys are separated from each other by stone floors. They are connected by steps built into the south-eastern wall. Originally, however, there were no steps between the first and second floors. There are two vertical spaces within the walls. One of them, a well cut in stone, opens directly onto the third floor. The well is 21 metres deep. Water from the well has been analysed and found to be suitable for drinking.