You'll find the 'Ancient Gate' day camp on the walkway here. Slide down to the muddy square and look to the right/west to spot a [LAID TO REST - #2 EFFIGIES]. There's some [SALVAGE] on the left/east side of the square. There's also a [SALVAGE BAG] hanging from the walkway in the southeast corner. Climb the stairs directly left of the mud slide and walk over the walkway. Blast out the barricade (this is all on the east side) to find [SHOTGUN SHELLS] and [DOCUMENT - #5 DIARIES OF A MADMAN (BELIEF)] inside.
Shantytown South - Collectibles part 1.
Wade through the mud and collect the [ARROWS] and [SHOTGUN SHELLS] on the walkway to the south. You can find more [SALVAGE] in the adjacent (left) walkway, in the red chopper wreck.
Move over the bridge and another shootout commences. There'll be a lot of dynamite hurling, so keep moving from crate to crate while killing enemies in the distances. If you keep hurting or kill the guy at the top, sounding the alarm, the battle will be less long than usual. [400 XP]. Search the place to find [ARROWS x6], [RIFLE AMMO] and [SHOTGUN SHELLS]. After this you can start exploring the area for optional items and collectibles.
• Drop down the platform to find a [GPS CACHE]; it's not in the river itself but still on this lower walkway among some debris.
• Climb the rope to reach a walkway with some [SALVAGE] in the corner, and an [XP BOX] on the other side, still on the same floor.
• Climb the structure (or rope) further to reach [SILENCER - #2 ALARM].
• You can spot [LAID TO REST - #3 EFFIGIES] on the tower you're supposed to reach (with Grim inside), it's to the southeast from here.
• Before climbing the next rope all the way to the top, first drop down to the walkway below again and destroy the barricade on the west side to reach an area with some animals and items. To the immediate right (after going through this hole in the fence) you can find [RIFLE AMMO] and [ARROWS].
• Move over the wooden bridge and drop down in the middle to find a [GPS CACHE].
• [RELIC - #3 INRO (COMMANDER'S INRO)] can be found inside the building, on the ground floor.
• Climb the building to find a [LARGE SALVAGE BOX] on the first floor.
• There's also a barricade around the corner (still on the first floor). Behind this lies a [GPS CACHE].
• Look all the way up at this spot, and you should be able to see a [SALVAGE BAG] hanging from one of the walkways.
• Scramble up the nearby wall to find [RIFLE AMMO] and an [XP BOX].
• Move up another level and some enemies appear in the distant building to the northeast. There's an explosive barrel near their position, so blasting it sure helps in this (small) firefight. After dispatching the remaining enemies, search the place to find [SHOTGUN SHELLS] and some [ARROWS] near the crates.
• Climb the building here (not where the enemies are; we'll get right to it) to find [SILENCER - #3 ALARM].
• From here, move south to reach the walkway you'd have taken if you climbed the rope immediately up. You can find [ARROWS] and [SHOTGUN SHELLS] here.
• This is also an excellent spot to locate the [LAID TO REST - #4 EFFIGIES] on the rock wall to the west.
• You can find some [ARROWS x2] on the platform north of the alarm.
After getting all those items, move to the northeast of the walkway (to where you killed several enemies.)
Shantytown South - Collectibles part 2.
• To the left of this intersection you can find [ARROWS]. Destroy the barricade and look for [RIFLE AMMO] and [RELIC - #4 INRO (SCRIBE'S INRO)] inside this small room.
• Before scrambling up the wall, move around to the right side and look behind the crates to find a [GPS CACHE].
• Scramble up the wall and some enemies appear at the windmill. Kill them and search the platform you're currently on to find [ARROWS] on the right side.
Once you reach the windmill you're up against another group of enemies. Dispatch them and start searching the area for the following items:
• Move to the left/north where the crates are being transported back and forth. You can find some [RIFLE AMMO] here, and you can also scramble up the wall just around the corner to find [SILENCER - #4 ALARM].
• Climb the mill to the top to easily spot [LAID TO REST - #5 EFFIGIES] on the rock wall to the northeast. There's in fact another one on the east side of the mill - perhaps in case you missed one.
• While on the top of the mill, search behind the central structure to find [ARROWS], [SHOTGUN SHELLS] and [RIFLE AMMO]. There's a [GPS CACHE] on the other side, again close to the central structure.
• Back at where the crates are being transported, move east to the fence, then look left to spot an [XP BOX].
• Drop down and circle the mill on the first floor to find a [SALVAGE BAG].
• Move to the ground floor to search the area underneath the mill. You can find [RELIC - #3 ANIMAL STATUARY (JADE DRINKING VESSEL)] on the north side of this area, [DOCUMENT - #6 DIARIES OF A MADMAN (OBSESSION)] on a desk to the west (underneath the stairs), and some [ARROWS] next to another set of stairs nearby.
• On the ground level, search the pile of bodies/debris west of the mill (not too far from a burning barrel) to find a [GPS CACHE].
• Still on the ground level, move to the southwest corner to locate a barricade. Destroy it and search the area behind it to find [SHOTGUN SHELLS] and a [PLANT].
• Not too far from here - still on the ground floor in the southwest corner - is a fence that's half-open. Behind it is another alarm (for if you've missed one, presumably). Drop down to the area below and search for a [GPS CACHE] in the corner near the fence. Destroy the barricade (and a second one in the hall behind it) to reach an [XP BOX].
Shantytown South - Collectibles part 3.
• From the 'Windmill' base camp (which is southeast from the mill), look behind the old corpse tree to find some [SALVAGE]. "Hey mommy, let's play count the corpses!"
• Head over the river north from the base camp and move past the boilers to the far north. Head upstairs and search the corner near the bench and the beam to find a [GPS CACHE].
• Move over the beam to find [SALVAGE x2]. A little further to the right/east of here you can find an [XP BOX] and a [LARGE SALVAGE BOX], plus some [ARROWS] next to the burning barrel.
• The cage contains [SALVAGE BAG x5]; in order to shoot them all down (with burning arrows) you'll have to shoot some from the ground floor (through the cage holes), and others will need to be shot by moving up the iron catwalk on the other side.