This is a hexagonal chess game board with 11x11 squares.https://en.wikipedia.org/wiki/Hex_(board_game))。The chessboard is divided into two parts for printing, which can be joined together to obtain a larger chessboard than what can usually be printed on an A1 printer. When I used support-free printing, the dovetail joint worked well, but if it doesn't work for you, you may need to enable support.

The chessboard in the photo was printed using an A1 printer, Elegoo PLA+ filament