Mind you the nice items on the drop-table list are really low chance!!! Expect to get a lot of 84e's and roughs!!!
Castilla Treasure Hunt:
Fortunately this hunt has both fixed spots and fixed time in Castilla Ruins on both channels,
Time Schedule (in server time):
Sunday till Thursday: | 00:00 | 03:00 | 09:00 | 12:00 | 15:00 | 18:00 | 20:00 | 22:00 |
Friday & Saturday: | 00:00 | 02:00 | 04:00 | 06:00 | 09:00 | 11:00 | 13:00 | 15:00 | 17:00 | 19:00 | 21:00 | 23:00 |
Each treasure hunt lasts 10 minutes, and starts slightly later then 00:00 (aka around 00:00 and 30seconds)
Spots i know off:
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To find the chest you need to spam detection, rouse and/or Whole Cancelation but detection has the best range and cooldown of the 3.(and costs no star orbs), The chests will usually be near the centre of the cross in my image but do have a tendancy to move slightly (still same room but just a few steps to the right).
To open it you need a ancient relic or gold ancient relic, either will work but gold should give better chance of a nice item:
Droplist:
(* stands for unverified, most of it is data of jge and havent found such drops here yet.)
-84e weapon / 30 ar weapon / 32 ar weapon*
-ELB / LN* / 27 dr armors / 84e armors
-ELB recipe* / LN recipe* / 92e recipe
-Artisan recipes / Qualified recipes / made necklace recipes
-Rough stones / Elemental Jewel / DHR / top tier jewel recipes
Sources:
ge_2ch jap wiki / Madam's diary, a jp blog