Carcassonne: The River II
This expansion includes twelve more river tiles for your Carcassonne game. Now you can make a longer river to start the game with and even better it has a branch tile so you can get the effect of two rivers instead of just one. Three of the twelve tiles also have effects taken from the Inns & Cathedrals expansion, the Traders & Builders expansion, and the Princess & Dragon expansion (note that these tiles can just be used ignoring the effects if you do not own these expansions).
The River II contains twelve new tiles and a small instruction sheet.
The River II is not a stand alone game. The original Carcassonne is required in order to use this expansion. As noted above, other expansions may add to the play experience, but are not necessary for use.