Ostentor keep is the capital of ostentor_district in Coranan province.
Note: there are discrepancies in the Atlas Hârnica maps over the location of Ostentor, with the E7 map showing it in the margin in F7 and the F7 map showing it in E7. Neither map names it visibly, though a search will reveal a hidden hit in the whitespace. The larger maps of Hârn have it in F7.