I'm not 100% positive that Adventure Comics #260 is the first appearance of the lighthouse or not. As far as I know, its the first origin story of the Earth-One Aquaman, so this is likely accurate, though I'm not positive.
Oh... and I know that the current pic is kinda crap. If I find a better one, I'll replace it. --Brian Kurtz 18:25, 8 December 2008 (UTC)