I don’t really know if there is any real lore about the gates of Zharr and I personally imagined it more like the black gate of Mordor. But your giant portal take is definitely cool. Are you going to continue to work on it, or is it finished?
Its 75% done. The wooden bridge and some wooden parts will be color shaded. And the Plan is to build some stone towers on a wooden substructre above it.
And there is pretty less to find about the Gates of Zharr. This is just my interpretation