Lake Goldajärvi
(Published on 26. December 2025, 13:58 by EdTheAlchemist)
Lake Goldajärvi marks the triple-point between Norway, Sweden and Finland; in the centre of the lake is a stone cairn with a little platform around it just so you can run around the triple point! I'm really happy with this puzzle and I hope you enjoy it too; if you like it, please remember to rate it and recommend it to your fellow solvers!
Sudoku: Normal Sudoku rules apply.
Norway, Sweden and Finland (Three-Way Yin-Yang):
- Divide the grid, except for the grey central cairn, into three colours.
- All cells of each colour are fully orthogonally connected.
- No 2x2 square contains four cells of the same colour (the grey central cairn counts as its own colour for this purpose).
- All three colours have at least one cell orthogonally touching the grey central cairn.
Seaweed (Seeing German Whispers):
- Any two cells directly connected by a green line differ by 5 or more.
- Any two cells directly connected by a green line are in different colours.
- Any cell on a green line counts the number of cells of the same colour it sees in all four cardinal directions, including themselves. Other colours, and the grey central cairn, block line of sight.
- ALL such seeing cells are on seaweed lines; any cell not on a green line does NOT count cells of the same colour in that way.
Fishes (Arrows):
- Any cell with one or more arrows counts the number of colour changes in the indicated direction(s) combined, counting from its own cell (so, if the edge directly in front of the arrow is a boundary between colours, the count includes that boundary)
Buoys (White Kropki Dots):
- Any two cells connected by a white dot contain consecutive digits.
Solution code: Row 8
Comments
on 29. December 2025, 17:07 by Glasgow
Very nice puzzle! Beautiful use of the ying yang yong and the begative constraint.
on 29. December 2025, 06:12 by m_or
Even as a Danish person, I can't find fault in this puzzle. Really fun. Thank's for making it!
on 28. December 2025, 00:15 by Prince Joffrey
fantastic puzzle
on 27. December 2025, 18:10 by GojiCrafter
The negative constraint was awesome, great puzzle!
on 27. December 2025, 15:34 by Franktothejay
Really loved this puzzle. Somehow I never believe a puzzle will have a negative constraint unless the words "Negative constraint" appear in the wording--even when the rules clearly indicate it. That's my problem--and to the credit of the puzzle, I think the solver reaches a point regardless where we have to re-read the rules and realize it's there.
on 27. December 2025, 13:57 by GoodMorningCallum
Excellent puzzle. Really enjoyed the concept of it, and I did my best to use colours faithful to the flags of Norway (red), Sweden (yellow) and Finland (dark blue). The negative constraint was interesting and very powerful too.
on 27. December 2025, 01:36 by Hengist
brilliant theme, brilliant rules, brilliant flow! this really tickles my 'tism
on 26. December 2025, 23:52 by oskode
Nice use of the negative constraint. Cool puzzle, thank you!
on 26. December 2025, 21:03 by Asphodel
Wonderful and never unfair, thanks !
on 26. December 2025, 19:41 by little_turd
This puzzle tickles the brain, in much the same way a sledgehammer tickles the concrete it smashes. Very well done.
