In recent decades, the island of Lesvos (North Aegean, Greece) has become a stepping stone on migrants' routes to Europe, attracting volunteer tourism aimed at providing support to migrants. Using the theoretical framework of Lefebvre's triad, we investigate Lesvos as a lived space for volunteer tourists, the representations of the island space they carry and their spatial practices not only as volunteers but also as tourists. The choice of where to go to volunteer depends upon wider geopolitical context, and volunteers' destinations (e.g. reception centres) are, stricto sensu, their working spaces. Nevertheless, during their free time, volunteers leave these spaces; specifically, we investigate this dimension of their experience. Through a survey, interviews and participant observation, we illustrate how volunteer tourists imbue the space of Lesvos with symbolic meanings, thus confirming their role in the humanitarian borderscape of the island; we further examine the ways in which they challenge the preconceived imaginaries of the island. Concurrently, we show how in specific places in the island's capital Mytilene, the lived experience of volunteers creates deep connections between volunteers, migrants and locals, to the point that some spaces are co-produced or deeply transformed by the presence and practices of volunteers.