After leaving Arthur's court in Carlisle, Percivale came to a river wider than a crossbow could shoot across, dark, swift-flowing, and turbulent, though contained within its bed (i.e., the riverbed was deep?).
Following the riverbank, he came to a rocky cliff. Eventually, on that rock, overlooking a slope that ran down toward the ocean, a magnificient castle came into view. Facing the wide bay where sea and river fought, the castle had a turret on each of its four corners, a round outerwork, and a stone bridge fortified with more towers and ending in a drawbridge. This was the castle of Gornemant of Gohort, who instructed Percivale in knighthood and formally buckled on his right spur.
In telling Blancheflor about his last overnight stop before reaching her, Percivale says he does not know the castle's name, but the name of his host was Gornemant of Gohort. Considering how extraordinarily naive Percivale still is at this point, I rather think that Gohort is indeed the name of Gornemant's castle with its surrounding territory, and that Percivale's failure to understand this is part of the joke. Blancheflor's failure to point it out can be ascribed to courtesy.