Isana was the most significant river of Poritrin.
The river had formed a deep gorge with sheer rock walls; the waters were treacherous but it was part of the vital trade route downriver. Floating barges from the continental flat-lands passed through. Lord Niko Bludd had decided to put up a giant mosaic on a canyon wall to commemorate his noble family beginning from the north towards the south. Around this point, Isana had a tributary.
The Starda city was built around its delta on the southern end and it was an important point of commerce; it was always seen busy with cargo barges, driftbarges, boatcars and boats loaded with cargoes of grain, fermented grass juices, flowers, local spices and raw metals from mines far to the north, delivering them to the manufacturing centers. South of the main city of Starda, the delta widened, leaving numerous flat islands separated by deeply cut shipping channels.
Around that point, the river melted into a slurry of water and muck where mudflats spread out in a broad fan and slaves planted smears of salves; across the mudflats were found factories and shipyards.
It was traditional for honored guests of Starda to wash their hands with a bottled water of Isana and dry themselves on fine linen. The Buddislamic slaves let cremation rafts flow on the river and take the burning bodies away from the city, and the ashes are carried out to sea.
The Isana had sour and peaty from silt and vegetation dragged down from the highlands.