The dm_prison.zip file you have requested: Maps Levels Missions / Deathmatch / O to P Titles / DM Prison - 2.06mb is not available. Perhaps try browsing all files for the game Half-Life 2 and upload any files you want to share or are missing. This is the only information we could locate:
This map is based on the Prison map from the Half-Life 2 singleplayer. Ive made the map with extended sewers which takes you from one corner of the map to the other. The watch towers have a mountable machine gun which is controllable by the player. This map is based on the Prison map from the Half-Life 2 singleplayer.