Wikipedia
Knockmealdown is the highest peak of the Knockmealdown Range of mountains, located on the border between Co Tipperary and Co Waterford. The peak itself is located in County Waterford and is the highest point in that county. However, since the county border generally follows the summit line the main peaks are actually in both county Tipperary and in county Waterford (OSI Discovery Map 75). Of the more prominent peaks to the east of the 'Vee' road — Sugarloaf, Knockmealdown, Knocknagnauv and Knockmeal sit on the border, Knocknafallia and Knocknanask are in County Waterford and Knockshane, Crohan West and Knocknasculloge are in County Tipperary. The same situation is true for part of the nearby Galty mountains where the highest peaks are shared between Tipperary and Limerick.