You'll take on a lot of quests that send you to the Dam Battlegrounds in Arc Raiders, including one from Tian Wen who wants you to search for Major Aiva's Mementos in some apartment buildings. This is a straightforward quest on paper, but because there are multiple buildings to explore and the ever-looming threat of ARC and other raiders, it's best to know right where to find these mementos so you can get out quickly.

Since you need to extract with Major Aiva's Mementos, it's a good idea to ARC Raiders BluePrints equip an augment that lets you store an item in a safe pocket. Once you pick up the mementos, you can toss it in that safe pocket and take it home with you even if you end up dead before you can extract.

With that out of the way, let's find Major Aiva's Mementos and wrap up The Major's Footlocker quest in Arc Raiders.

When you arrive at the apartment complex, you'll want to head into the leftmost building. The item you're looking for is on the top floor (not the roof). Head up two flights of stairs, then wrap around and follow the rooms until you reach a dead end with a window and a box on a desk in the corner.

As stated above, you're required to extract with this item. Hopefully, you have a safe pocket slot! Either way, your closest options are likely to be the Central Swamp Lift to the south or the North Complex Elevator to buy ARC Raiders Materials the east. The safer choice is probably the latter, as the former tends to stay pretty busy with other players perusing the swamp for mushrooms and other quests. Whichever you choose, play things safe and get out alive, raider.