Tràng An is a Vietnamese government supported cultural and ecological park development covering 2,500 hectares that is centred on an isolated massif on the southern edge of the Song Hong delta in Ninh Bình Province, north Vietnam (Fig. 1). The archaeological investigation of Tràng An is being led jointly by the Xuan Truong Construction Corporation and the McDonald Institute for Archaeological Research, University of Cambridge, under the direction of the lead author. The Corporation is creating an ecologically sensitive development – the ‘Tràng An Tourism Resort’ – within this karstic landscape, which is also the subject of a planned application to UNESCO for World Heritage Site status. International involvement in this work has been at the behest of Nguyêń Van Truong, the General Director of Xuan Truong and at the invitation of the Ninh Bình People's Committee. The research itself is carried out under the guidance of Nguyêń Van Son, the Tràng An Tourism Resort Project Manager. The main focus of the May 2007 season was to undertake excavations at the site of Hang Boi (the ‘Fortune-Teller's Cave’).