Befallen was an undead dungeon located in the Commonlands in EQ1.
When EQ2 was being developed, the designers decided to 'update' Befallen for use as a dungeon in EQ2 as well.
However, (apparently after the graphic artists had already completed their work for the 'new' Befallen), a decision was made to 'change' it into the dungeon of Stormhold (which had not existed in EQ1), and move the already completed 'Befallen' to Antonica, keeping all the artwork and layout from the original Befallen, and simply changing the name to Stormhold.
The substitution was less than perfect, and it was rather obvious what the developers had done. They even kept the file name as Befallen, which is why you saw it when loading.
There is an extensive discussion on the subject on the previous pages of this forum here:
http://eqiiforums.station.sony.com/eq2/board/message?board.id=lore&message.id=5279
and here.
http://eqiiforums.station.sony.com/eq2/board/message?board.id=lore&message.id=4446