Theater in gorgeous outdoor settings can be somewhat critic-proof, especially when the show in question takes place at the top of Mount Tamalpais. If you're in the mood to pack up cushions and take a lovely, zigzagging drive with the intention of getting sunburned in an amphitheater, then it won't matter to you that Mountain Play's production of Man of La Mancha is solidly mediocre. The 1965 musical — loosely based on Don Quixote — is pretty weak material to begin with, in part because its clumsy play-within-a-play structure keeps the audience at arm's length. That said, this production has at least one solid point in its favor: William Elsman's Don Quixote is exactly as hammy and lovable as he should be. But without a strong Aldonza, Man of La Mancha will always come up short — not least because her self-titled number is the show's most powerful song (and no, I'm not forgetting the karaoke standard "The Impossible Dream," diabolical earworm though it may be). Another major problem here is the choreography, which renders the play's key fight sequences as perplexing jumbles. But if the prospect of so-so theater doesn't concern you so long as you're looking down on Mill Valley from 2,400 feet, then just go.