Glenmore or Dalraddy, both near Aviemore
I can thoroughly recommend Dalraddy. Found it really welcoming, half the pitches are private in the trees, good facilities.
Holidays in the heart of the Scottish Highlands
Glenmore is nice, but when we went it was really crowded with queues for showers and loos.
Comrie Croft – classic spot that is just so the brilliants, good riding locally on gravel and of course MTB.
https://www.comriecroft.com/
Rannoch – Kilvrecht is a basic loos only site, but cracking riding around the blackwoods or over to Bridge of Balgie.
https://forestryandland.gov.scot/visit/forest-parks/tay-forest-park/kilvrecht-campsite
Ballater – loads of Deeside riding, the campsite is big and busy, but community owned and some of the best facilities (and pubs) we’ve been to.
http://www.ballatercaravanpark.com/
Anwoth at Gatehouse of Fleet, – cracking wee site and facilities, amazing pubs (live music festival when we went) and brilliant Galloway riding from the door up hills or along coast.
ANWOTH
Left field….Port Mor on Islay – community owned, cracking view, superb food at the cafe (mainly veggie & vegan), riding is all sorts rather than gravel.
http://islandofislay.co.uk/campsite.php