Amongst the plethora of new content that was announced at Vanafest 2010, Square Enix announced three new add-on scenarios for the parallel world of Abyssea. From new, ferocious notorious monsters to brand new equipment in styles reminiscent of Artifact and Relic armor from days of old, these new scenarios garner towards those adventurers who aren't feint of heart willing to test their mettle against hordes of new challenges.

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From Playonline.com:

An announcement was made today at VanaFest 2010 for "Abyssea," an all-new three-part series of battle-oriented add-ons.

A parallel world existing beside Vana'diel, Abyssea is a land fraught with perils and home to savage hordes of heretofore unseen creatures. Ferocious, towering NMs, new-look HNMs?even the garden varieties will confound would-be challengers with their unfamiliar and formidable powers. These and a whole host more await hapless adventurers with open arms and voracious maws.

In Abyssea, concerns such as the over-population of battle areas and the need for large time investments will be a thing of the past. The development team is hard at work creating a world where parties can engage in rewarding battles with powerful foes and collect prized equipment with the least of fuss.

More details are available via the following links:
The Official Abyssea Website
The Official VanaFest 2010 Website