<p>The interest in the documentation and enhancement of Underwater Cultural Heritage (UCH) is rising rapidly over the last decades. This has happened especially due to the significant technological advances, which have enabled the digital data acquisition in the hostile underwater environment. Numerous efforts have been made so far concerning the 3D digitisation and promotion of the UCH using photogrammetric methods and 3D surveys in order on one hand to document the site and on the other to develop virtual and augmented reality applications and make this part of the hidden cultural heritage accessible to people with difficulties to reach it.</p><p>This paper presents the methodology, the actions and decisions that were taken for the geometric documentation, study, promotion and enhancement of the remains of a roman villa located at Agios Vlassis, in Ancient Epidaurus in Greece. The present effort focuses on the use of low-cost equipment in order to acquire the necessary digital data to produce the 3D textured model of the archaeological site and the required 2D documentation products. The methods used to produce this 3D model involve contemporary computer vision algorithms adapted to confront the challenge of processing a huge number of images and extracting useful metric information from them. Moreover, the creation and programming process of two virtual reality applications is described. By developing a virtual tour and a virtual reality application, it is hoped to raise the awareness about UCH and give prominence to different means and ways of protection and management of underwater archaeological sites.</p>