The National Karst Database consists of point features, locating the centre (or in the case of a cave, the entrance) of karst landforms grouped into 8 types and records details of the landforms dimensions and functioning.Karst is a term used world-wide to describe the distinctive landforms that develop on rock types that are readily dissolved by water. In Ireland, karstification mostly occurs in limestone regions. As approximately half of the Republic of Ireland is underlain by limestone, karst is a significant aspect of the Irish environment. There are many kinds of karst landforms, ranging in size from millimetres to kilometres. For simplicity, these landforms are grouped into 8 main types in the National Karst Landform Database.