Los Padres [1] - This quaint town on the edge of lava destruction has no enemies to fight, until you get to -
Fort Dundee [2] - A good place for beginners and medium-level players alike. This place has loads of Navy soldiers, ranging from Sergeants to a few officers and lots of veterans. Good for bladed weapons and voodoo, maybe not so much for grenades. The jail on Padres Del Fuego was in Fort Dundee.
Beckett's Quarry [3] - From Fort Dundee or the Catacombs, you can find yourself in this very dangerous place for medium and beginner characters. The quarry is a silver mine in which Lord Beckett's prisoners are forced to work. The miners can they heal you for a low price of 5 gold, but the quarry is populated by some of the toughest Navy and EITC mercenaries in the game. Also, they are VERY close together, so it's easy to find yourself surrounded when trying to evade attacks. The code means use can't use your pistol, but you can dish out blades and voodoo.

Lava Gorge [4] - Really just a transition spot between the cave entrance and the Catacombs, since there is nothing here but a handful of undead and a couple of bats.
The Catacombs [5] - Accessible from the far side of the island or from a side-entrance through Beckett's, this room contains a number of tough undead and more EITC and Navy baddies. There are high-level undead gypsies, undead raiders and unead grenadiers as well as veterans, officers, hired guns and assassins. There is also a platform where Jolly Roger overlooks the fighting.

El Sudoron [6] - The lush jungle between Beckett's Quarry and Las Pulgas is full of hard to find critters (Stumps, Dread Scorpions, Gators, Fly Traps) as well as a Navy camp with a couple of EITC bad guys too. A great place to find quest enemies. Most of what is in here is good pistol practice. Blades, Pistol and Voodoo can all find plenty of opportunity.
Las Pulgas ("City of Pests") [7] - On the other side of El Sudoron is a small town overrun with undead, and a few valiant Navy. This area can also be reached by swimming left around Padres Del Fuegos from the dock area. The bad news is the residents are all high-level undead gypsies, undead grenadiers and undead raiders. Good news? The village offers all the stores of a regular town and an escape to your ship is a short hop away. As in the quarry, mixing humans and undead makes pistol hard, but cutlass or voodoo is a good option. A group of mediums or a handful of higher-level characters can take advantage of this isolated area.