I parked in a carpark near or in boot when I went up to see White Moss & Brat's Hill. It's nice up there, I could imagine it without the peat as a lovely safe enclosed valley.

Personally though, I'd favour the Pike of Stickle stone axe factory, as others have said. And I say that having seen 80% of the circles in the lakes district.
The view from the top is amazing and you get to see where the folk that built the circles actually started off those wonderful green lakes axes. Thats all wow to me!