Here is a guide to navigating your way around the maps of Diablo 2's Act Three jungle areas. They feel endless and incomprehensible, but there's actually quite a bit of structure and order that you can learn to recognize.
(Apologies if you're viewing this on a small device or viewport, but the full-size images are necessary. I assume if you're playing Diablo 2, you have a computer and can put down your phone.)
Here is an overview of an entire jungle area, from Kurast Docks in the lower left to the entrance to Lower Kurast in the northeast. I stitched this together from many screenshots. Let's break this down:
There are three named areas, of course: the Spider Forest, Great Marsh, and Flayer Jungle. Each of these is always a rectangle oriented with the long axis from southwest to northeast.
Coming from Kurast Docks, the jungle begins with the Spider Forest. The Great Marsh can be attached to any point in the Spider Forest. The Flayer Jungle can connect to any point in either the Spider Forest or Great Marsh. It can connect to both, as in this example, but that is not required.
Now let's break this down further:
Each area consists of a series of tiles as shown here. Each of these tiles is big, about twice the size of your screen at 800x600 resolution.
Each area is two tiles wide on the northwest-southeast axis, and six to ten tiles long on the southwest-northeast axis. This is always true, there are no exceptions, no single named jungle area is ever more than two tiles wide.
There are two types of tiles: river areas and alcoves. I'll start with the alcoves because they are simpler:
The entrances to each alcove are marked by a pair of stone pillars bracketing the way from the main jungle areas. These are the rules for the alcoves:
The alcoves contain the following (each from left to right in the example image):
Now let's look at the river tiles, and how you find your way through this.
The rules for these:
Now you know how to use this to your advantage. When you're looking for the quest locations within an area, follow the river tiles and check out each alcove. And to find the next areas, this is the key configuration:
Suppose you've seen the teal tiles (in the Spider Forest) and enter the purple tile and see that it has a connection on its northwest side. You know for certain that must connect to a different area, because you've already seen the two-tile width of the Spider Forest, and a third tile along that axis within the same area is not allowed.
You don't know until you enter that next area if it's going to be the Great Marsh or Flayer Jungle (and there's no way to tell which one any particular exit from Spider Forest might be), but you know right away that it will be a different area. And if it is the Great Marsh first, there is no way to tell where the Flayer Jungle will be attached until you enter the tile that will connect to it, although you can cut down a few possibilities by knowing the possible alcove arrangements.
So overall, no, this guide doesn't and can't tell you exactly how to skip through the jungle areas and find the exits. There's only a few small tricks and shortcuts, no magic solutions. The general idea is always go northeast along the river tiles, and get what you need for the quests in the alcoves. But maybe this will help you navigate and save some time at least.