Gargoyle Point is a new area added by Castle Volkihar Redux for The Elder Scrolls V: Skyrim. It is the entrance to a new dungeon in The Elder Scrolls V: Skyrim specific to this mod's storyline quest It's Good to be King.
Gargoyle Point is located on the north east side of Volkihar island (the back side). Although you could swim there the best way to get there is by taking a small boat at the Volkihar shipyard docks (boat does not become a functioning fast travel marker until the quest It's Good to be King reaches stage 20).
The entrance is adorned with giant gargoyle statues. The door is gigantic and the knob to open it is that of a gargoyles head. There is a boat at its platform which ferry's the Dragonborn to the Volkihar Docks.