This is a list of mountains in Britain and Ireland by height and by prominence. Height and prominence are the most important metrics for the classifications of mountains by the UIAA; with isolation a distant third criterion. The list is sourced from the Database of British and Irish Hills ("DoBIH") for peaks that meet the consensus height threshold for a mountain, namely 600 metres (1,969 ft); the list also rules out peaks with a prominence below 30 metres (98 ft) and thus, the list is therefore precisely a list of the 2,754 Simms in the British Isles (as at October 2018). Many classifications of mountains in the British Isles consider a prominence between 30–150 metres (98–492 ft) as being a "top", and not a mountain; however, using the 30 metres (98 ft) prominence threshold gives the bro