Poipu's beaches are the point of staying here. Conditions vary with swell and season, but the south shore is often calmer and sunnier than Kauai's north side, especially in winter.
Start with Poipu Beach Park for swimming and families, use Kiahuna Beach when you want a simpler sandy strand, and head east to Shipwreck Beach when you want space and surf-watching rather than an easy snorkel.