A “County Top” is the highest point of a county, and topping all the county tops is a worthy endeavour.
Amongst the ninety-two counties of the United Kingdom there are 90 county tops (as each of Ben Macdhui and Sawel Mountain tops two counties). The Irish Republic has 23 county tops, as three are shared (and on both lists is Cuilcagh, the county top of both Fermanagh in the United Kingdom and of County Cavan in the Republic).
Map of the county tops
*County tops article on Wikishire