D'ábel's Island is situated on the east coast of Prehevil.
This area can be reached from a pier at the Lake, but it can only be accessed by taking a boat that's only present on Day 3 Night (if Karin is alive before Day 3 Night).
Abella: "It's bizarre... No matter how I tried to look for the opposite shore, I couldn't see it... It's as if this island is the only thing that exists in the mist."
Abella: "And here I thought the boat was our one way ticket out of the horrors of Prehevil..."
Daan: "It's the same as when I tried to walk through the misty forest to get away from the city... You just end up circling around and eventually drift back to your starting point."
Daan: "I thought it was just me, but you couldn't row past this island either..."
O’saa: "Something clearly wanted us to come here to this island... but what?"
Trivia
Although there is functional (and unique) Party Talk dialogue for this location, the boat to reach D'ábel's island does not appear until Day 3 Night, meaning that it's impossible to view through regular gameplay as all party members will have Moonscorched by that time. Also, battle backgrounds exist for Day and Evening times at this location as well, which go unused for the same reason.
The ingame name "D'ábel's Island" is spelled with an apostrophe after the letter "D"; however, the proper spelling should be "Ďábel's Island", with a caron above the letter "D" instead of an apostrophe. The mistake likely originates from the lowercase form of the word, "ďábel".
Both the English and Bohemian forms of the name literally translate to "Devil's Island".