This achievement is in Half-Life 2.
Start a new game from Black Mesa East. If you haven't gotten that far or lost your save, there's a cheat code that will unlock all levels for New Game. Sit through the cutscenes until Alyx takes you out into the scrapyard and hands you the gravity gun. Once you have the gravgun, ignore anything Alyx says and climb up on the box to your right (if you are facing the wall where the Gravgun was) and use the crate to climb up onto the concrete platform. You will see the old HEV charger faceplate from the original Half-Life sitting against the wall. Pick it up and look at it for a while and the achievement will pop.