Information on this one from our catalogue: Clare Island is in Clew Bay, Co. Mayo. The tower house in the photograph is known as Granuaile's Castle. A tower house is a medieval fortified house and was the stronghold of the O'Malley family, and it was most closely associated with Grace OMalley, the sixteenth century pirate queen who controlled a large section of the west coast. The tower house was later used as a coastguard building. Fish curing was an important industry on the island, the people at work on the beach are packing barrels with cured fish, and the barrels are stacked around the harbour. The Congested Districts Board became involved in the island in 1895 and encouraged the industry as a means to improve the local economy. This is the main harbour on the island.

beachcomberaustralia provided this link for an internal tour of Granuaile's Tower House, aka Carraigahowley or Rockfleet Castle.

Date: Circa 1897 as a starting point? (presumably after 1891 as the CDB was set up in that year, and after 1895 as the industry looks well established?)