Forza Horizon 4

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):

Forza Horizon 4 has a total of 12 Beauty Spots available at any time during the game. To trigger one, just drive up and interact. All 12 can be seen in the video below with available timestamps underneath:
Timestamps:
[0:49] - Derwentwater
[1:23] - Mortimer Gardens
[1:50] - Glenfinnan Viaduct
[2:15] - Scott Monument
[2:42] - Arthur's Seat
[3:07] - Bamburgh Castle
[3:31] - Moorhead Wind Farm
[3:56] - Derwent Reservoir
[4:24] - Whitewater Falls
[4:51] - Uffington White Horse
[5:16] - Broadway Windmill
[5:40] - Ambleside Village

A guide to show all 12 Beauty spots in Forza Horizon 4 for the "Taking the Grand Tour" achievement. At the end of the video is pictures of the map with the spots circled.

Here is the guide to get them all:

Step by Step guide showing all 12 beauty spots across the map. Each spot has its own narrated cut scene and grey out after being activated. Timestamps are below:

Timestamps:
[1:31] - Ambleside Village
[1:55] - Broadway Windmill
[2:13] - Uffington White Horse
[2:36] - Derwent Reservoir
[2:58] - Whitewater Falls
[3:20] - Derwentwater
[3:44] - Mortimer Gardens
[4:07] - Glenfinnan Viaduct
[4:47] - Scott Monument
[5:12] - Arthur's Seat
[5:37] - Moorhead Wind Farm
[5:58] - Bamburgh Castle