The dm_octagon.zip file you have requested: Maps Levels Missions / Deathmatch / O to P Titles / Half-Life 2: DM Octagon Map - 29.94mb 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:
For more information on Half-Life 2, visit Halflife2.filefront.com This is a very nicely done Half-life 2 death match map by Swot. It uses custom textures and HDR lighting on an indoor environment.