Turns out there are bosses everywhere in Elden Ring Nightreign, including the top of the castle that is normally a pain to clear out. Reddit user Aphod posted a clip showing how to scale its walls and reach the boss sitting on top, bypassing tons of enemies on the way. I hopped into a solo run to test it and, yeah, it totally works.
The castle is always located in the center of the map unless you have a Shifting Earth event going on, and the tightening circle tends to end somewhere nearby. The place is always filled with tough enemies scattered throughout its ramparts, but you don't actually have to fight them if you know where to jump. That said, I'd recommend coming here once you're at least level eight.
