My computer gave up the ghost in 2016, so I'm not really up to date on what's good now. Anyway, maybe you should take a look at Carbonite (it's an addon). Please keep in mind that it is a large modular questing addon, but, it has it's own maps that SOUND like they are just what you are looking for. I realize it's not exactly what you're looking for, but it might give you some ideas.
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Ahhhh, the vagueries of the aging mind. Wait.... What was I saying?
Carbonite <----- GitHub main module (Maps ONLY) download link. The other modules are also available on GitHub.
Carbonite-CLASSIC<----- GitHub link to Carbonite Classic. Thanks to ircdirk for this!