Spawning objects at points within another object?

My group has a bunch of random chunks of map that spawn, but within those chunks we want to set some sort of anchor points or gizmo or however unity does this, points where other objects, small groups of models such as crates or background details should spawn after it spawns the larger map chunk.

How would we achieve this? How do you set some sort of anchor or location where other objects should spawn, and then reference to it and make things spawn there?

Thanks!