There are 24 location tiles with 8 new abilities and 12 summary cards for the edges of the board. There are 4 new board quadrants with the Marshes land type on them. Castles have been replaced with Forts adding a different scoring possibility. To go along with this new land type, 5 Marsh terrain cards are added to the terrain deck.
What makes the Marshlands expansion unique are the bonus abilities. For they include new abilities, a bonus ability is unlocked if you manage to collect that ability twice. For example, if you have collected the Rider ability, you may move one of your pieces into an adjacent land hex. If you collect a second Rider, then in addition to getting to move twice via your Riders, you can also jump one piece in a straight line to the first empty land hex.