Henry's Promenade is the large tavern on the south side of Isle Fortuna.
Henry's Promenade can be found overlooking the ocean of the south side of Isle Fortuna.
There are two entrances to Henry's Promenade. There is the front entrance, which brings you to the front of the tavern. Then, there is a back entrance, which has several barrels outside it. The back entrance is locked, unless you have a quest allowing you to enter that way.
Going through the front entrance, you emerge in a large room, with many NPCs and parlor game tables. The room is a loft, and on the second floor landing is private rooms, which you can rent and put your items in.
Under the floor of the second floor is the bar. There, a bartender named Thomas Shell can be seen. There are two doors behind the counter. One leads to the back exit, and one leads to a back room. (Note: you can only get behind the counter for a quest. Glitches do not work.)
In the back room, there is a small desk, a bookcase, and several crates. In one corner of the room, there is a trapdoor that goes into the cellar. The cellar is small, but larger that the one at Rumrunner's Isle. The cellar, however, has a little secret. There is another trapdoor.
Following the next trapdoor brings you into a small tunnel. It's been carved out, so there are beams holding the dirt in place. Looking straight across from the trapdoor ladder, there is a makeshift door. Using the makeshift door, you come into another tunnel, which is about the same length. There, a mine elevator awaits you, to enter Fortuna Caverns.