You may know Sudoku as the fun and sometimes maddening logic puzzles that help pass the time on the beach, in the airport, at the kids’ soccer practice. But wait until you’ve tried Hawaiian Sudoku. It definitely gives new meaning to the phrase “thinking outside the box!”

Delwyn Higa, a master engraver of Hawaiian heirloom jewelry, has turned traditional Sudoku on its head. In Hawaiian Sudoku, he’s thrown out the traditional square grid and replaced it with circular puzzles in Hawaiian-style motifs like honu, volcanoes, and Hawaiian drums. What’s more, these puzzles must also be solved diagonally, in lines that cut across poi pounders, hibiscus, and pineapples.

Puzzles by: Delwyn Higa