Glass furnace regenerators having opposed pairs of side and end walls formed of refractory blocks, wherein at last one of the side and end walls of the regenerator comprise an interlocking plurality of refractory blocks, and wherein the refractory blocks are self-supporting and load-bearing one-piece pre-cast structures of a refractory material. Tie back bars may be provided to operatively connect a wall formed of the refractory blocks to externally provided buckstays to allow relative movement between the refractor blocks forming the wall and the buckstays (e.g., as may be required due to the blocks undergoing thermal expansion during use).