1:39:13 The city is surrounded by water, which was covered with another layer of grass or clover field terrain. I doubt you can get there with waterwalk. You probably need summon boat. One of the shrines near the cove player should have it and the admirals hat is also available on the map through a quest chain.
Nice. Good job of beating that map! and finally the most expected homm5 playthrough is coming out. hopefully you'll get a shot on the map I've sent to you. It's a fun and challenging one. Take care!