舞台

1. Origins, structure, and basic meaning

• Structure: 舞台 (ぶたい) can mean a performance stage or a figurative setting for activity.
• Basic usage: An actor 舞台に上がる onto a physical platform; a city is noticed 活動の舞台として as a setting.

2. Common pitfalls and similar expressions

• Platform entered by an actor and city serving as a setting
  • Physical location uses に; capacity or function uses として. The city in the second sentence is not a theater stage.