This Settlers of Catan board requires the base game, Seafarers expansion, Cities & Knights expansion, and also the 5 & 6 player expansions for each of the game variants. This board is dominated with a large river that cuts the board into northern and southern landmasses. Good spots are hard to come by and choosing good starting places depending on your strategy is key to winning this board. You can choose whether to play with 4 to 6 players because even though it uses the expansion pieces there is not a huge amount of land to make 4 players out of the question.
You can do a couple variants to further change this board setup. The gold pieces from Seafarers are flipped over into water hexes in these images but could be uncovered to provide two gold hexes at the left/right end of each side of the board. This will provide a great option for players to build to be escape the two main landmasses. You could alternatively place a small deck of random resource/progress cards in that space instead if you do not want to go the gold option.