My 17th Century Dutch isn't so good but I can still look at the illustrations in Johan Picardt's 1660 book "Korte beschyvinge van eenige vergetene en verborgene Antiquiteten" eg here, here and here. Mr Picardt is considered the founding father of the study of archaeology in the Netherlands. The drawings seem to show the hunebedden being built by giants and dwarfs. But the dwarfs seem to get the raw end of the deal as the giants end up eating them. That's certainly what it looks like at any rate.
Throughout Europe and even adjacent areas there was the widespread belief in thunderstones. These peculiar stones (prehistoric flint and stone axes) were thought to have crashed into the earth during a lightning strike. Although nowadays this superstition has largely vanished, it was still widely accepted in the first half of the 20th century.
Deinse* describes this situation for the Dutch province of Overijssel, directly south of Drenthe. He reports that virtually every farmer has at least one prehistoric axe at his farm. They were believed to protect the house against lightning, as lightning never strikes the same place twice. He even reported that particular axes were believed to possess special powers. Small bits of stone were scraped off these axes and were given to children as a medicine against convulsions.
Deinse, J.J. (1925): Uit het Land van Katoen en Heide - Oudheidkundige en Folkloristische schetsen uit Twente. p102-111
This is from p25 of 'Ceci n'est pas une hache. Neolithic Depositions in the Northern Netherlands' by Karsten Wentink, 2006 - which you can read online at Google Books - it has lots of Serious archaeological information and discussion in it.