In the present study, through analyzing two pieces of writing (Epistula 25 and In Theodorum) by the 4th-century Cappadocian father, St. Gregory of Nyssa (A.D. 334/35–395), I intend to focus on the relationship between sacral places or spaces and memory in the Early Christian cult of martyrs, more specifically, in the case of martyria. Although these pieces are not related to one another, both can be considered paradigmatic from the aspect of the current topic. What is more, their joint reading and analysis would be expressly desirable because the epistle provides the external layout of the construction of a martyrion that, as far as we know, has never been completed, while the homily contains a description of the interior of another martyrion, which still existed during the lifetime of St. Gregory of Nyssa, elaborating in detail also on how the memory and laudation of the martyr saint were related to the sacred location and space. Following the clarification of the concept of martyria and providing a brief outline of the religious-theoretical and architectural contexts, through a joint interpretation of the two pieces of writing, I will attempt to address the issue of what kind of religious and symbolic associations helped communal memory in the sacred space determined by religious and liturgical functions to cherish the cult of martyrs and thus strengthen the faith of the community.