This is the Keep from B2, from the 1979 TSR module by Garry Gygax, rated the 7th greatest module of all time

I posted
it previously, but noticed the front portcullis had disappeared. I
fixed this, but have accidentally deleted the original post. Duh.

Anyway, here it is.

There is a 4500 x 5000 version on my Patreon page, here.