The wisdom of the windmill. How a windmill works. One kept in good repair lasts centuries. Whoompa. Whoompa. In the old days, the whole family could live inside. To adjust the whoompa, jam in the log brake to stop it. without bisecting yourself, and adjust the fabric covering, or take it off completely. See more at http://www.edinformatics.com/inventions_inventors/windmill.htm
- The mounds at Jelling, on Jutland DK,are more like this one. Harald Bluetooth set his runestones and reburied his father from a mound there. Even if the Jelling sites substantially predate the era of Harald Bluetooth, 10th Century; would the date be pressed back as far as 1700 BC. See http://whc.unesco.org/en/list/697, See also http://denmarkroadways.blogspot.com/2010/10/jelling-harald-bluetooth-rune-stones.html. Perhaps, if the structure had been simply reused over time.
- Even Ladyskibet DK is Viking era, 950 AD. http://www.vikingdenmark.com/ladbyskibet-ladby-denmark.html
- Gamla Uppsala, in Sweden, is 500-800 CE. http://swedenroadways.blogspot.com/2011/02/old-uppsala-gamla-uppsala-royal-burial.html
Our amateur vote goes with Viking era for these, 800-1050 CE or so; or at least not before 500CE. Still looking.
3. Wind blows free
Rural areas enjoy good roads, one lane or two. Slow up, pull over, room for both.
You can always take the prefab Marguerite Route in Denmark, to see all the foreordained sites, see http://www.visitdenmark.com/international/en-gb/menu/turist/oplevelser/attraktioner/sightseeing/the-marguerite-route.htm. Or use it as a sequencing device, if you do not have the time to see every inch of Denmark. The full map is at http://www.visitdenmark.com/international/en-gb/menu/turist/kort/kort/map-of-denmark.htm. We rambled instead.