Athlone is an Irish town located on the western border of the province of Leinster. It lies on the River Shannon and has a population of 21,349. The town is built around Athlone Castle, built in the 12th century. The castle remains standing up until today and is now open to the public as a museum. The town also features a promenade on the River Shannon, and is very popular among anglers, birdwatchers and swimmers. Athlone also became a major retail destination, housing two large shopping centres, and numerous hotels.