Castle Peak Bay (Chinese: 青山灣) is a bay outside Tuen Mun. Tuen Mun River empties into the bay. In the past, many Tanka fishermen harboured at the bay.
There are several barbecue sites and recreation facilities near the bay including the Castle Peak Beach and other beaches. Castle Peak Bay is served by MTR Bus routes K51, K58, KMB 52X and 53.
Coordinates: 22°22′N 113°58′E / 22.367°N 113.967°E