The sdk_de_i_rock.bsp file you have requested: Maps Levels Missions / Others / S to T Titles / Yes it's another cs:s map - 703.73kb is not available. Perhaps try browsing all files for the game Counter-Strike: Source and upload any files you want to share or are missing. This is the only information we could locate:
You can open the large metal doors which lead to the 'sniper' tower, and the two sides of the long red platform are climb-able. Two bases, kill each other, etc.