What appears to be a layout for map 0xDA00
Map 0xBD00 is a glitch map in English Pokémon Gold and Silver.
Going to this glitch map by modifying addresses 0xDA00 to 0xBD and 0xDA01 to 0x00 may result in a special red Glitch Dimension with flipped sprites, nicknamed the flipped sprites mode.
The specifics as to which sprites are flipped vary based on unknown factors, and the flipped sprites can go away at some point later in the game.
The 'flipped sprites mode'