Advance
Saharan Caravan Stop
Trade between sub-Saharan Africa and North Africa has been part of our identity for centuries. The journey across the vast desert, even with the many years of accumulated experience, is always taxing and dangerous. The key to securing trade in this region is the Caravan Stop, a place where merchants and their caravans can rest and refresh themselves on their way through the desert.
Advance tree
The game files don’t say where this goes: it has no requires, so the game places it in the 
Traditions tree itself.