The river has a taxi service called the "Rio Taxi." It is very expensive per ride (like almost $10). But for $15 per person, you can hop on and off for 24 hours! So, while still expensive, it is so fun and relaxing, plus you can get to a lot of different places without walking! So Tuesday evening we bought tickets and rode most of the day Wednesday, too. :)
Some of the sites:
At each underpass, a local "artist" was given the privilege of decorating it. So each one was totally different. Some were really beautiful, some were weird and some were...
One section of the river has just been renovated in the past few years, and it I think 8 or 9 feet higher, so they have locks for the rio taxi to pass through: