The archaeological site of Caral [http://www.caralperu.gob.pe/principal_ing.htm] is 1 hour inland by unsealed but adequate road. Peru's government recently formally opened it for tourism. Labelling & facilities are good once you get to the site, from Pativilca, Barranca or Supe, all of which are on the Panamerican Highway.
Enjoy a beatiful walk down to the beach of Puerto Chico and watch a beautiful sunset. If you are an early riser, you will see the fishermen bring in the daily catch. You may choose to take a mototaxi for 1 sol to avoid the walk uphill back in to town.
Sit down and catch a breeze at the Plaza de Armas (People's Square)and meet the locals and maybe enjoy a street comedy improv.