staging area

noun
1
an area where soldiers and equipment are gathered before a military operation
منطقه تجمع, منطقه آماده‌سازی
2
a place where people gather to organize an activity or a trip
محل تجمع, محل تجمع موقت, محل تجمع اولیه, مکان تجمع
The church was used as a staging area for the flood relief effort.