Ten of the best plays within plays

At the Guardian, John Mullan named ten of the best plays within plays.

One entry on the list:
The Seagull by Anton Chekhov

The guests at Sorin's country estate gather to watch an experimental new play by his nephew, Konstantin. The young playwright's neighbour Nina stars in this symbolist hokum and takes the stage to perform a long and rambling monologue about the nature of a universal soul.