There are 12 beauty spots in total acrooss the map, each one appears with a purple icon before it's been activated. When you drive up to the marker, press X and you'll get a narrated cut scene and the spot will count as being found, the icon will then turn to grey on your map.
The locations are:
Glenfinnan Viaduct in west of Glen Rannoch
Mortimer Gardens north of Derwent Water Lake
Derwent Water west of Lakehurst Forest
Whitewater Falls, south of Lakehurst Forest
Derwent Reservoir, east of the Derwent Quarry
Ambleside Village in Ambleside
Broadway Windmill just south of the Horizon Festival Site at the bottom of the map
Uffington White Horse east of the Horizon Festival Site at the bottom of the map
Moorhead Wind Farm east of Lakehurst Forest
Bamburgh Castle, on the east coast just south of the lighthouse
Athur's Seat south west of Edinburgh
Scott Monument in the center of Edinburg
Screenshots of them all below (in grey icons):