Ten maps. Still nothing to do with Doom despite the name.
On the Shores of Hell (1 map) and Beyond the Shores of Hell (10 maps) are a pair of clearly related First and Second (respectively) Encounter mapsets by Jon Bair. As is so often the case, we don't know anything about the story between them, and even the authorship of the latter one is in small doubt as Clubey was unable to establish it conclusively; really though, everything points to Jon Bair, including mapping style. And speaking of mapping style, the bigger mapset shows steady progression in difficulty and you will be fighting some rather terrifying, dangerous gauntlets in late maps. Other than that it's pretty standars: mostly close quarters combat with a couple minor mazes in the mix. Still worth it.
===CREDITS===
Jon Bair