Arthur's Seat was a point of contention. Apart from having to convince two teenage girls that climbing it was a good idea, we parked at Holyrood. Ignoring the 'Only park here for the palace' signs, we set off up the steep hill, only to realise after a slight descent that we'd set off from the wrong place and that conquering the 'seat' would involve an even-steeper climb.
Mountaineering was abandoned for the day but, even halfway up, the views were stupendous.
Oh dear - there is a very easy way up to the summit, but that's about a mile from where you parked. Basically, if you follow the road to the right, round the foot of the crags and the hill, you come to a bit where the road is fairly close to the summit, and there's a rough footpath to the top ... I'd have given you more info if I'd known you were going by car. For some reason I assumed you'd be using public transport. Still, you got the views. Had you come the weekend before you'd have seen absolutely nothing because of that awful east coast phenomenon known as a haar, or scotch mist.