on a high

:  rising or extending upward a great distance :  taller than average, usual, or expected

:  having a specified height or elevation :  tall

:  situated or passing above the normal level, surface, base of measurement, or elevation

:  at or to a high place, altitude, level, or degree

:  well, luxuriously

:  an elevated place or region: such as

:  hill, knoll

:  the space overhead :  sky