The River Cuale divides Puerto Vallarta in half and runs around a small island at the point where it enters the Bay of Banderas. That island is the site for a host of shops and restaurants, shaded by many trees. It's reached by stairs from each of the two main bridges which cross the island, and by many hanging walkways which cross to the old town on the south. It's very picturesque, cool, and relaxing--and in the trees above, there are iguanas feeding.
We went to see the museum on the west end, but found it under renovation and closed. That likely was the result of Hurricane Kenna, which also closed some of the resorts due to flooding. The river was just a trickle during our visit, but the rounded stones in the stream bed attest the flow during the rainy season. The abundance of those rounded stones also explains why cobblestone streets are so common in the city.