[This is a repost from our archives with new notes at the top (original post here): This puzzle highlights a lot of the standard Cave logical thinking (including a rule about checkerboards that we mentioned in a prior post needs to be in your toolbox for this genre). If you are struggling with this cave puzzle, an “Ask Dr. Sudoku” written piece may be worth referring to.
or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)
Theme: “23” – Both the original posting date in 2013 (Jan 23), and a fine number for themed logic puzzles, such as the Map Puzzles from Bang 23.
Estimated Difficulty*: 2.5 stars
Time Standards (highlight to view): Grandmaster = 1:45, Master = 3:30, Expert = 7:00
Note: Follow this link for classic Caves and this link for Cave variations. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.