Also called the 'Big County' (its unusual feature is that while it is Scotland's 4th largest county, it is one of the most rounded in shape in the UK) it is almost at the geographic centre of Scotland. With Perth in turn at its centre, the Perthshire boundaries are from Strathmore (east), to the Pass of Drumochter (north), Rannoch Moor and Ben Lui (west) and Aberfoyle (south).