Following the survey activities and implementation of small coastal test pits since 2012, during  2016-2017 field work seasons, the excavation pits have continued to be carried out by Vietnam Maritime Archaeology Project Team (VMAP) both in the coastal area of ​​Cong Cai Bay and in the Son Hao village (Quan Lan Island, Van Don district, Quang Ninh province).  In addition to structural remains of the harbour, architecture, residential buildings and wells, a large number of artifacts are discovered, especially glazed ceramic, stoneware, porcelain and metal objects. This paper discusses initial results of research focused on the characteristics of the archaeological sites and provenance of the artifacts recovered. The results of this project will help clarify the important role the Cong Cai – Son Hao region played in the historical development and operation of Van Don – the first international trading port in Vietnam. This resource also contributes to clarifying trade activities in the Gulf of Tonkin, which was an important stopping point in the international maritime network of the region.