Exclusive Internal Skyscraper Loop
(Published on 28. June 2025, 01:40 by yttrio)
Rules:
Normal Sudoku rules apply.
Draw a one-cell-wide loop of orthogonally connected cells. The loop may not touch itself, not even diagonally.
Cells with arrow clues are internal skyscraper clues. Each cell in the grid represents a skyscraper with a height equal to its value. A digit in a clued cell gives the number of skyscrapers visible in the indicated direction (not including the cell itself), where every skyscraper blocks the view of all skyscrapers with the same or lower height behind it.
All cells seen as skyscrapers from a clued cell must be on the loop. All cells in the direction of the clue not seen as skyscrapers must not be on the loop.
6x6 Example:
The image below shows a sample 6x6 puzzle and solution with the same rule set.
Play the example 6x6 in SudokuPad.
Solution code: Digits on the loop in row 6 (left to right) followed by digits on the loop in column 7 (top to bottom)
Comments
on 29. July 2025, 13:10 by apokrupto
I’ve recently made the move from two star puzzles to three stars and this was my Everest! Four restarts, many hours, but so worth it in the end
on 20. July 2025, 15:36 by BorisP2101
Terrific puzzle, the bottom part of the loop was very tricky for me :D
on 5. July 2025, 13:52 by Agent
Beautiful!
on 29. June 2025, 11:45 by Exigus
Lovely puzzle with a very smooth flow. Thanks!
on 29. June 2025, 10:43 by Franjo
Thank you so much for creating and sharing another one of your fantastic loop puzzles. I love them all.
on 28. June 2025, 22:38 by Snue
Very nice - thanks for the puzzle :)
on 28. June 2025, 19:57 by tryote
Lovely!
on 28. June 2025, 15:07 by Calvinball
It's amazing that there is enough information in this grid not only to solve, but to solve so smoothly. But it is a yttrio puzzle, so I don't know why I'm acting all surprised.
on 28. June 2025, 13:21 by Snookerfan
Nice and smooth, thank you!
on 28. June 2025, 10:43 by marcmees
great loop construction. Thanks
on 28. June 2025, 05:58 by JaesonD2
Really challenging, but great concept!
