Yalong Bay is Sanya's earliest developed upscale resort area. Hotels like Marriott, Hilton, and Ritz-Carlton — mostly built 2008-2015. Hardware is slightly dated but well-maintained. The biggest draw is the best beach in Sanya: fine sand, gentle slope, clear water — ideal for families with kids. Downside: 20km from downtown, so dining and shopping are mostly hotel-bound, and prices run high.
Haitang Bay is the newer district developed after 2010, home to Atlantis, Edition, and Rosewood. Hardware is fresh, design is striking, and amenities are complete (duty-free mall, rice park, Global Food Street). But Haitang Bay has strong winds and rough currents — swimming is banned most of the year, so you're limited to hotel pools. Best for pure resort stays, diving trips to Wuzhizhou, and duty-free shopping runs.
Sanya Bay is the closest to downtown, just 10 minutes from Phoenix Airport. Hotels are cheap (300-600 RMB gets you an ocean-view room), and the Coconut Dream Corridor sunsets are stunning. But the sand and water quality are noticeably worse than Yalong or Haitang, and crowds are dense. Best for budget travelers, nightlife lovers, and those who want downtown convenience. As a middle ground, Dadonghai is a solid pick — close to downtown, decent beach, good hotel value.