This Destiny 2 Outskirts Lost Sectors page will explain where to find all the mini-dungeons within that area of the EDZ / Earth Patrol space.
If you want more information on how to find Lost Sectors and the rewards they offer, our Lost Sectors locations page can help.
Destiny 2 Outskirts Lost Sectors
The three Lost Sectors in Outskirts are:
The Drain location
Location: Underneath the broken road just past the large fountain as you enter the Outskirts, you'll find three Fallen defending a tunnel entrance. Look above the door for the telltale symbol.
Strategy: It's very easy to get lost in this dungeon, so follow these tips. Head inside the tunnel, and turn right when you reach the first chamber. Follow this tunnel, then take a right to enter the right area. In here you'll find Shanks, Dregs and, of course, another boss.
There's a lot of room for flanking against you, so focus on taking out the Fallen to your right (as you enter), and those camping at the edge of chamber. The boss will likely retreat up a flight of stairs to the left of the chamber, so pursue him and end him to claim your rewards.
Try hanging back with an auto-rifle or sniper rifle if you're playing solo at a lower level. Go in a hand cannon or side-arm if you're Level 20 and cause some chaos.
Whispered Falls location
Location: Head to the location on the map in the screenshot, you should see the Lost Sector symbol on a wooden plank at the bottom of a small hill.
Strategy: Behind that hill, look for an almost impossible to see cave entrance (see screenshot). Head through and drop down into the chamber with the stalagmites.
Take out the Fallen and enter the brighter area. Use the raised areas to reach the top of the room, but beware of losts of Dregs and Vandals peppering you with fire at the bottom of the room. A well placed grenade will finish them off. Enter the opening and you'll encounter the boss and his Fallen minions.
Focus on the Shanks and the Vandals, as it's easy to be overwhelmed with fire in this small area. Remember to avoid letting those Dregs get too close as they cause heavy melee damage.
The area is pretty tiny, save for one raised area at the back so head on over once the ranks have been thinned out. Wear down Keldrik's shield and overwhelm him to gain your prizes.
For Season of Plunder, we have the Sails of the Shipstealer quest, Treasure Coordinates and Map Fragments, Cryptic Quatrains and weapons such as the Quicksilver Storm and Taipan 4FR. Meanwhile, there's the arrival of King's Fall and King's Fall challenges, plus weapons including Doom of Chelchis and Touch of Malice. For The Witch Queen, learn how to get Exotics including Dead Messenger and Parasite.
Scavenger's Den location
Location: As you enter the Outskirts from the direction of Trostland, head past the giant fountain and head left of the broken road. Turn right and follow the hill to find the symbol for the Lost Sector.
Strategy: Head through the tunnel, turn right so you see a large banner in front of you, then turn right to enter the first area. Be wary of the sniper to your left-hand side. Take out the captain hear to move onto the next area.
Try and take out Shanks first as they can do lots of damage in groups and be wary of Marauders sneaking up on you. Take out the second captain, then head for the tunnel at the rear of the room.
Destroy the laser charges in this tunnel (don't get too close, they cause tons of damage).
You'll now be in the main area (it's got a ruin in the middle of it with a red banner at the top). Clear out most of the boss' minions first (Shanks especially as they can overwhelm you in groups_, then ascend to the highest platform to take out the boss and claim your loot.
Flanking to the left-hand side is a good strategy for lower level players as there's plenty of cover.