Castle of knights on the left or past boat ride on the right - which area is recommended to do first?

[kalirion]

Both these areas have regular enemies with EXTREMELY tanky HP compared to my puny damage (~40 per sword hit). Which area is recommended to do first? I'm thinking castle because at least I can jump over to skip the knights, something that can't be done with the giant enemies on the right....

Or am I missing something? I still don't have the grappling hook or whatever is supposed to let you get across the rings.

Edit: Nevermind, did the Castle (Cathedral, it seems) first, which gave an ability to open up a better area with yet another ability. But damn that Cathedral boss was hard, ended up buying a couple Large Health Potions to be able to beat her.