An apparatus for producing one or more pre-cast concrete structures. The apparatus may include partitions that may be positioned in a side by side arrangement. The partitions may be moveable with respect to each other to facilitate installation of reinforcing material and removal of the concrete structures from the apparatus after the concrete has hardened. Cavities may be defined by the partitions for receiving concrete to form structures having panels with integral columns. The columns may include slots for receiving an adjacent panel such that adjacent concrete structures may be joined together to form a continuous wall. The partitions may also include interchangeable liners such that different textures or finishes may be applied to the concrete structures.