I've found the entrance to the underwater city and I found some chests outside with a ocean amulet or so. But int the city after some meter I end in front of ... it seems to be a door with a octopus. What should I do next to get access to the city?
Thanks
Piquoy

Look for a lever.

Wyv

Probably wrong place, same I tried. Real entrance is under big Temple ruin, it has big crack on one side on bottom, swim in and you will get to dungeon. Be sure to have undewater helms and airshells.