I've been thinking a bit about the fiefs in the vicinity of Lake Vejápa, in particular that island I've plonked down in the middle of the lake. I've intentionally made it so that is always an island whereas the others only become islands for 3 or 4 months of the year.
The above picture of the monasteries at Meteora, in Greece, illustrates something of what I am aiming for, only the rock outcrop is an island. On top would be perched a monastery/temple to Lady Avánthe. My assumption is that this temple would administer a fief centered on the lake.