A large field of blocky sea-floor hills, up to 10km long and 500 high, are gigantic slide blocks derived from the west flank of Mauna Loa volcano on the island of Hawaii. These megablocks are embedded in the toe of the south Kona landslide, which extends ~80km seaward from the present coastline to depths of nearly 5km. A 10-15km-wide belt of numerous, smaller, 1-3 km-long slide blocks separates the area of giant blocks from two submarine benches at depths of 2600 and 3700m depth that terminate seaward 20 to 30km from the shoreline. Similar giant blocks are found on several other major submarine Hawaiian landslides, including those north of Oahu and Molokai, but the South Kona blocks are the first to be examined in detail using high-resolution bathymetry, dredging, and submersible diving. Dredging of two of the giant blocks brought up pillowed tholeiitic lava. Megablocks were carried by a late Pleistocene giant landslide 40-80km west from the ancestral shoreline of Mauna Loa volcano before growth of the midslope benches by later slump movement. -from Authors