The chests inside these buildings are bugged, and have an unusually high chance to drop high runes up to Ber in Hell difficulty. Therefore this area is often 're-rolled' on single player until a 'perfect' seed is found, where the campfires spawn close to the area's waypoint.
This allows you to open six chests within around 30 seconds, making it the fastest way to farm high runes.
Normal: 1 - 2
Nightmare: 4 - 6
Hell: 7 - 9