This restored tower house of six storeys stands on a narrow rock outcrop above woodland at the end of a laneway off the main N18 road. There is no date for when it was built, but in 1579 it was the cause of the deaths of Dermot O'Shaughnessy and his nephew John, who fought and killed each other in a dispute over possession of the castle
Here is a short clip on youtube of the castle up close on youtbe
This five-storey tower house was built in the 16th century by the O'Shaughnessy family. Sir Roger O'Shaughnessy was succeeded by his brother Dermot, the Swarthy, known as the Queen's O'Shaughnessy for his support of the Crown. In 1579, Dermot and his nephew John fought each other hand-to-hand in a dispute over the castle. The fight resulted in the death of both men. It stands on an elevated site and is partially surrounded by its original defensive wall. The castle has undergone recently extensive renovation and now it is a National Monument.
Here is a link with more detailed pictures of the castle; http://irishantiquities.bravehost.com/galway/ardamullivan/ardamullivan.html