Carrantuohill or Carrauntoohil are different spellings for: Highest Mountain in Ireland. The Carrantuohill Rise is almost a folk sport for the Irish. There are several hiking trails to reach the destination. The Carrauntoohil or Carrantuohill is the highest mountain in Ireland. With its 1041 m summit he is not particularly high, but still no easy climb, if you start from the Black Valley.