Lackland AFB is located in San Antonio, Texas. It is primarily a training base. Hailed as the "Gateway to the Air Force", it is the only site for U. S. Air Force Basic Military Training. Tech schools and such are also on base.
Adjacent to it is Kelly Air Force Base. ("Kelly kills" is a reference to the quality of the drinking water) Lackland started off as a division of Kelly, in fact, and was called the San Antonio Aviation Cadet Center (SAACC, or just "Sad sack" for its crappiness in layout). In Air Force tradition, the base was later renamed after Brigadier General Lackland.
A few miles away is Medina Air Force Base which was recently renamed to Lackland Annex, but everyone calls it Medina anyway.