Base Exterior - Well-Defended Building and Mini-Boss with Shield - Part 1

Exit the ruined building through opening on the left (east) side and climb onto the wall ahead (or just jump from one ledge to grab the other and pull up).

When you do, more enemies appear in the next building and launch their attack. A few slide down the zip line onto the ledge where you're standing.

If you can shoot them off the rope as they slide...

...they'll fall to their deaths.

If not, just deal with them when they reach you. Others stay under cover and throw Molotov cocktails and shoot flaming arrows.

Maybe you're more nimble and aggressive than I am, but I prefer taking out the enemies one or two at a time, from behind cover if possible. If necessary, you can jump back down into the area where you were before. Good places to hide include the sandbag wall and the low cement barrier to the left of it (marked with X's in the screenshot above). Both are between the ruined building and the ledge leading to the next area. You'll need to climb back up onto the wall now and then to get the attention of the remaining enemies, but you should be able to kill most of them this way.

You can hide and snipe at a few of the men up in the building. Here Lara is shooting from behind the sandbags.

Here she's behind the low wall with the bottles on top.