The Malara (Anuru Bay A) Macassan trepang-processing site was investigated from 2008 to 2010, to test two chronological models of the timing of cultural contact between north-west Arnhem Land and South-East Asia. Currently, the models of contact between South-East Asian people and Australian Indigenous people are a “long model” of pre-Macassan and Macassan contact (>200 years) and a “short model” of only Macassan contact (<120 years). The aims of this study were to assess when the site was first occupied, when intensification of site use occurred and when the site was abandoned. This assessment was undertaken by radiocarbon dating of the major trepang-processing features, the two burials at the site and several other occupation areas. Bayesian analysis of the 18 radiocarbon dates gives 80% probability that Indonesians first used the site around AD 1637. Trepang processing intensified during the middle to late eighteenth century, consistent with the known expansion of the Macassan trepang trade. There is a final occupation and processing phase in the late nineteenth century. We discuss issues regarding the “old” radiocarbon dates from trepang-processing sites. We argue that our investigations support the “long model” of cultural contact between Asian visitors and local Indigenous groups.