My sense is the Smurfs were probably inspired by **Brigadoon**, a very famous Broadway musical ([Lerner & Loewe][1]) that was adapted into a very famous film starring [Gene Kelly][2] and [Cyd Charisse][3].  

>  The story involves two American tourists who stumble upon Brigadoon, a mysterious Scottish village that appears for only one day every 100 years. <br><sub>[Brigadoon (wiki)][4]</sub>

The name Brigadoon derives from the real [Brig o' Doon][5], a bridge near Alloway, Scotland, and a feature of Robert Burns' folkloric poem [Tam o' Shanter][6]. 

It's possible the Brigadoon story derives from folktale, but I'm not fining any reliable online sources. However, I found an excerpt attributed (without specific citation) to a book *[Lost Lands, Forgotten Realms: Sunken Continents, Vanished Cities, and the Kingdoms That History Misplaced][7]* which reads: “the spell that was cast over Brigadoon was put in place to protect it from advancing English Redcoats during the Jacobite Rebellion.”


  [1]: https://en.wikipedia.org/wiki/Lerner_and_Loewe
  [2]: https://en.wikipedia.org/wiki/Gene_Kelly
  [3]: https://en.wikipedia.org/wiki/Cyd_Charisse
  [4]: https://en.wikipedia.org/wiki/Brigadoon
  [5]: https://en.wikipedia.org/wiki/Brig_o%27_Doon
  [6]: https://en.wikipedia.org/wiki/Tam_o%27_Shanter_(poem)
  [7]: https://www.goodreads.com/book/show/757443.Lost_Lands_Forgotten_Realms