prosceniums

A proscenium is a architectural feature of a theater that frames the stage. It consists of an opening in the wall between the stage and the auditorium, with a surrounding structure that can include columns, a decorative arch, or a gilded frame. The proscenium arch effectively creates a "picture frame" through which the audience views the performance. This design emerged during the Renaissance and became dominant in Western theater architecture from the 17th century onwards.

The primary function of the proscenium is to separate the audience from the performance space, creating a clear distinction between the world of the play and the reality of the theatergoers. It also helps to focus the audience's attention on the stage and can conceal stage machinery, lighting equipment, and backstage areas. The area between the proscenium arch and the stage floor is often called the "apron."

While the proscenium stage has been a staple of theatrical design for centuries, its dominance has been challenged by alternative stage configurations such as thrust stages, arena stages, and black box theaters, which offer different relationships between performers and audience. However, the proscenium remains a common and recognizable theatrical form.