Most of the lava flows in North Kona originate from the last eruptions of Hualalai, in 1800 and 1801, although some flows by the resorts hail from Mauna Loa. You will no doubt notice the white graffiti dotting the vast lava fields. This has been going on for decades, and locals still get a kick out of it, as do visitors. The first thing everyone asks is "where do the white rocks come from?" The answer is that they're bits of coral from the ocean, and if you want to write a message, you've got to use the coral that's already out there. This means that messages don’t last long, but that's all part of the fun. Some local couples write their names in the same spot on the lava fields every anniversary. Other people greet friends as they arrive or depart Kona.