This study investigated three aspects: how project-based collaborative learning facilitates cross-cultural understanding; how students perceive project-based collaborative learning implementation in a collaborative cyber community (3C) online environment; and what types of communication among students are used. A qualitative case study approach was applied to explore these aspects using a variety of data sources. First, students' reflections were evaluated to determine their level of cross-cultural understanding. Second, students' messages on the discussion board were analysed to explore their cross-cultural learning process and types of communication. Third, interviews were conducted with the students and their instructor to investigate their experiences and perceptions with respect to project-based cross-cultural learning. Results of this study show that cross-cultural learning took place in the 3C online environment. Folk games, learning activities, were interesting, drew students' attention, and stimulated their motivation. The students and the instructor positively perceived the 3C online environment as it created an authentic learning environment by connecting students from different cultures. Educational, technical, and communicative types of communication in the 3C environment were derived; however, only communication of the educational type could facilitate cross-cultural understanding. Based on the results, this study provides implications and suggestions for the teaching and research community in the field.