Possible Clues:

• High level above earth
• An atmospheric layer
• Atmospheric layer
• Extraordinarily posh retreats somewhere far away
• Flying to stars, reduced pressure in this place?
• Sherpa travelling with rest to high region
• Spotters hear cuckoo in part of the sky
• These parrots must suffer, reaching such height
• Cloudophobia?
• Elevated position in Mad Hatter’s prose