Normal sudoku rules apply.
In addition, numbers in the central blue 7x7 area represent skyscrapers of that height. Numbers in the viewing spots, highlighted in green around the border, represent the number of skyscrapers visible along the corresponding row/column. Taller skyscrapers will hide shorter ones behind them.
Pleased to say this was featured on Cracking the Cryptic!
You can solve it on f-puzzles here.
Solution code: Enter the digits from the bottom row:
on 18. July 2023, 07:16 by uvo_mod
Added Sudoku tag.
on 18. September 2020, 22:58 by SudokuExplorer
Nice break from killer sudokus, thanks for the puzzle!
on 9. September 2020, 09:56 by Savia
Added CTC link
on 26. August 2020, 22:09 by dm_litv
@Rollo: So what? The solution is unique without this observation.
on 25. August 2020, 00:15 by Rollo
All green fields are given!