Observe the beautiful Mosaic's in the town, including a 20' 3-D mosaic of Jesus ascension into heaven. Other ones can be found across the various plazas.
Go for a walk along the Malecon, the walkway along the river.
Get out to the beaches in Aguas Verdes, or Puento Pizarro to see the Manglares, or eat lunch on a small island only reachable by boat.