halong bay karst formations reflected in the emerald waters of tonkin gulf, vietnam

adventure asia asian attraction bay boat cliff coast cruise dawn descending dragon emerald exotic exploration explore explorer formation gulf halong heritage indochina island journey karst landmark landscape limestone lonely long mountain nam ocean peace peaceful rainforest relax rock scene scenic sea seascape ship stone sunrise sunset tonkin tour tourism tourist travel trip tropic tropical turquoise twilight unesco vacation vessel vietnam vietnamese view water world