This paper investigates the depiction of space in Hugo van der Hoes' Trinity Altarpiece, and discusses the altarpiece as a movable object related in a symbolic rather than literal manner to the space of the church in which it was displayed. This paper is based on existing interpretations of the altarpiece itself, of Van der Hoes' other work, and on research on the use of triptychs as a vehicle for meaning in fifteenth century Netherlands. By considering the triptych in the context of the Trinity church itself, the paper focuses on the role of thresholds in the painted spaces of the altarpiece and in the real-life space of the church, and brings forth a new interpretation of its likely position and usage. The paper also investigates the intentional overriding of perspective rules by Netherlandish painters in the context of current attempts at engaging with and representing non-Euclidean spaces in the context of Virtual Reality reconstructions.