I love weapons. I love how they look, how they feel... even how they smell. My favorite was the impossibly powerful weapon Mar built to blast open the Metal Head Nest. Poor fool died before he could use it. Aahh well...”— Krew, Jak II
Mar's gun is a weapon featured in Jak II. It was built by Mar, with intentions to use the Precursor Stone to blast open the Metal Head nest and destroy its inhabitants, though Mar disappeared before he could use it, and hid the stone in his tomb. It is an incredibly large structure, appearing to be made of steel, and, while highly distressed and weathered, appears to be painted a brick red.
Because the Nest was never destroyed, and because the structure is so large and durable, it may be presumed that it is still there to date.