a castle on top of a hill with a view of a lake

Long ago when me and my brother were young, we’d drive to Austria and come across this castle. We always wanted to stop, see and explore. Fast forward 15 years later we decided to go on a roadtrip and discover it for ourselves! Funny thing was, I was actually listening to ‘Ed Sheeran - Castle On A Hill’ when we parked the car and started our walk up the hill!