This article about the unknown age, construction, and purpose of about 70 round towers scattered about Ireland is a fascinating read overall, but a few choice quotes (from separate sections) are especially interesting because of the implications about energy:
“Using infrared photography, it has been noted that though there is clearly a roof on this tower, [...]
One of our dogs woke us up around 4:30 barking at coyotes howling in the distance. After that awakening, I finally got back to sleep just after I heard John’s watch beep for 5 a.m. It was still quite dark out. Next thing I know, I’m sitting up in bed, but feeling paralyzed, [...]