Here is the information for the first (and currently only) H3 dungeon in the new expansion. The door is in Aether Wroughtlands, and it uses the same map as the overland zone.
Code:
<ImageStyle Name="exp20_dun_aether_wroughtlands_04" displayname="Aether Wroughtlands: Native Mettle [Heroic III]" zonerect="-1494.00, -1137.00, 1464.00, 1082.00">
<ImageFrame Source="images/maps/map_exp20_rgn_aether_wroughtlands.dds" SourceRect="0,0,800,600" />
</ImageStyle>