Which recreational facility can be found only on Disney Dream and Disney Fantasy?

The AquaDuck is a unique water coaster that can only be found on the Disney Dream and Disney Fantasy cruise ships. This innovative attraction offers guests a thrilling experience as they ride on a continuous loop of water slides that travel over the sides of the ship and through scenic areas, providing both adventure and stunning views of the ocean. The AquaDuck stands out as a signature attraction that embodies the fun and whimsical spirit of Disney cruising.

In comparison, La Piazza is an area that can be found on other ships as well, and the Disney's Oceaneer Club is part of children's facilities that can be found across multiple Disney cruise ships. Similarly, themed dining rooms, such as Animator's Palate, are a common feature of all Disney cruise ships, offering unique dining experiences but not unique to the Dream and Fantasy specifically. Thus, AquaDuck is the correct answer as it is exclusive to the two mentioned vessels.