Joshua 10:10

Now we need to explain this. There are two places: just to the west of Gilgal, which is called Upper Beth Horon, and then a little further west there is Lower Beth Horon. Upper Beth Horon and Lower Beth Horon were connected by a mountain pass—narrow and very treacherous because it was a quick descent: the pass of Beth Horon. And this is where the Israelite army drove the Amorites. Now he mentions Azekah and Makkedah. Azekah and Makkedah were basically—on a map, you would see that it is probably about 14 or 15 miles south of Lower Beth Horon, maybe a little bit west. But to get to it, you had to go down the pass of Beth Horon and then around to get to Azekah and Makkedah. So the full length from Gibeon to Azekah and Makkedah was about 20 miles because they had to go in this roundabout way. And the first part, down the descent of Beth Horon—was very steep and treacherous. And then you were going through the valley of Aijalon. That is why it was so roundabout—because you were following the valley of Aijalon, which was the easier route than going up into the highlands around there.

So obviously, as an army is being chased from behind they will take the path of least resistance, and that is what they did. They went down the valley of Aijalon all the way as far as Azekah and Makkedah. Azekah, by the way, is the southernmost of those two cities. They would get to Makkedah first before they got to Azekah.