Inferno Cave (later remade into "Inferno Crater") was a dungeon found in early (and late) PMU 6. The original Inferno Cave was possibly made by Mazeyelle or Joel (previous members of the staff team. Verification required on the original creator).
Inferno Cave was a well-loved and received dungeon. The small design of the dungeon and early level 60-70 Pokémon made it a good place to grind. The dungeon was eventually closed to be remade. This upset the community.
Several months later, Inferno Cave was remade into Inferno Crater by Yatterman and Flare. The dungeon retained some of it's original layouts, but it received a new tileset and was extended into more floors. Inferno Crater was both a pre-mapped dungeon and a Random dungeon (15 Floors after the Mini-Boss were all random. At this time, Random Dungeons were still an uncommon thing).With the release of Inferno Crater, Darkmazer had made a change to his two dungeons (Pitch Black Abyss and Dynamo Sands), making Inferno Crater a requirement to enter those dungeons (both dungeons were moved to the island that housed Inferno Crater). These two dungeons at the time were the two hardest non-event dungeons in PMU 6. Inferno Crater was considered the 5th-7th hardest dungeon by players' opinions. This dungeon made a return in PMU 7 as Inferno Volcano.
Miniboss: Infernape, 2 Flareon (Added in Inferno Crater)
Set Level? No