I crest the hill and it's clear we're on the moor proper. The grass changes to swathes of sandy tufts. The wind is freer.
And here, beyond the crest in a dip, hidden from Down Tor, is the circle. A few cattle graze nearby, but other than them there is suddenly a sense of isolation. It's welcome. The stones seem to demand it.
Later at home I read this excellent blog that includes information on their alignment with the sun. https://www.dartmoorcam.co.uk/CAM/previouswalks/2018-1-25_DPA_DownTor/DownTor.htm