Octopus Garden. It's like a shipwreck filled with gold - also the blue-silver iron gorgets that you can get here make for great leveling EQ. If you swim down to the bottom, the Kraken makes a nice, easy AV run.

Walk ( 6s, ne, 2s, se, 2e, s, 2sw, s, 2e, u, 3e, 2s, se, e, ne, d ) to get from DH to the room marked in blue.