In an adult, the spinal cord ends at the level of:

In an adult, the terminal end of the spinal cord, called the conus medullaris, ends at about the L1-L2 level of the spinal column and the lumbar and sacral nerve roots descend as the cauda equina below this level to the lower lumbar and sacral exit neuroforamina. Spinal cord in adult  ends at lower border  of lumbar one vertebra. Spinal dura mater and arachnoid  mater extend till sacral two vertebra. Spinal pia mater comprises  an outer epi-pia  and an inner pia-intima. Reference: B D Chaurasia’s Head and Neck anatomy 6th ed page no 187