Banagher (Beannchar na Sionna in Irish) is a town in Republic of Ireland, located in the midlands on the western edge of County Offaly in the province of Leinster, on the banks of the River Shannon. The name Banagher comes from its Irish name, which translates to English as "the place of the pointed rocks on the Shannon". Banagher was a town of 3,000 people at the height of its economic growth in the mid-19th century. The current population is just over half of that figure, at about 1,600. Banagher has an important strategic position on the River Shannon, and was long one of the few crossing points between the provinces of Leinster and Connacht. It thus became a natural focus for many great historical buildings, including a 19th-century Martello Tower and a number of important castles around the town, which were built in the 14th and 15th centuries.