Two-dimensional hexagonally ordered CMK-3 carbons were synthesized using SBA-15 templates calcined at a temperature of 1153 K, whereas a disordered carbon was obtained using SBA-15 calcined at 1243 K, demonstrating that the pores connecting ordered mesopores in SBA-15 silica persist up to ca. 1153 K, but are eliminated at temperatures close to 1243 K.