Abstract: An improved block for making a horizontal, vertical, uneven and/or undulating surface has opposed upper and lower surfaces and opposed side surfaces. Sleeves extend through the block from opposed side surfaces and the sleeves on one pair of sides are at a different elevation from the sleeves at the other pair of sides. When blocks are placed to define a surface the sleeves align with sleeves in adjacent blocks and connecting ties are inserted through the sleeves to interconnect and stabilize the blocks. The blocks are preferably manufactured from concrete.