I found that with cup and rings. There's only so many rocks I can look at with three dints in it and remain interested :-)
I think my interest is cyclical too. It's good to do a few megalithic sites, but then take in the rest of the locale. Check out the local medieval church... bump into the neighbourhood history nut; have him show you the little-known Roman remains under the church floor (as happened to me in Humberside), go find the local Holy Well...
Talk to the oldies.
... then go to the nearest Alehouse selling nice beer.
Ahhh. Refreshed!
:-D
Back to my cup and rings....
;-)
Take care, FW.
Cheers
Dave