The rtcwspcastlekeep.zip file you have requested: Maps / Single Player / RTCW SP - Castle Keep - 7.01mb is not available. Perhaps try browsing all files for the game Return To Castle Wolfenstein and upload any files you want to share or are missing. This is the only information we could locate:
A lost island with the ruins of a castle. Your objective is to get to the top. Can you find the 3 secret pieces? There will only be 3 guards to eliminate.