The Iron Peak Army has mastered some tricks to deal with these types of fortresses.
The problem is that Bishop's Castle is situated on the riverbank, where digging just a few shovelfuls down will cause water to seep through.
In such circumstances, trench advancement is impossible.
Even when Montekucoli laid siege to Bishop's Castle, he only dug trenches at a somewhat distant, higher ground along the riverbank.
Incidentally, with the reversal of the situation on Magit Island, all the fortifications previously built by Colonel Monteccolli to blockade Bishop's Castle have fallen into the hands of Tamas, saving the warriors of Iron Peak County a lot of effort.
Trench digging becomes a self-trapping endeavor, roughly so.
However, this leads to another problem: Bishop's Castle is basically at the lowest point of its area, with the terrain steadily rising from Bishop's Castle to Domoncos Monastery, completely unobstructed.
