The Eramosa Karst is the Hamilton Conservation Authority's newest conservation area. It is located in the southwestern section of the Stoney Creek area of Hamilton. Karsts are geological formations including underground drainage, caves and passages caused by dissolving rock, found in limestone formations like the Niagara Escarpment. The Ministry of Natural Resources designated the Eramosa Karst lands as an Area of Natural and Scientific Interest in 2003. Several of its karst features are provincially significant. These include: soil pipes, a high concentration of suffosion dolines and sinking streams, overflow sinks, dry valleys and a 335 metre-long cave (the tenth longest in all of Ontario). There is also a natural dolomitic limestone bridge at the entrance of one of the sinkholes.