Definitely old school, in design and medium.
Sorry I am not from the old school so... is that good or bad?
You can't beat squared paper and a pen! My advice: don't feel you have to follow the squares - but by all means use them as a guide. Put in some wiggly bits, curves and the like to give your dungeon some variety. There is something great about seeing hand drawn maps and manuscript annotations though.
They are straight because they are the Underground of a temple... And they act as tunnels to the guys from there...
Xandor's Dungeon has some curves... post it later.
Thank you for the opinion!
Were the builders of those tunnels slaves or the temple priests? Unless they were slaves, I would suspect they wouldn't do 90 degree turns/jogs as that would take longer and require a bunch more effort and engineering to get them to be equal on both sides as in the first map you posted.
It would be more likely that they would have gone at a 45 degree angle to "cut" the corner and get around the center room. Just a thought. Back in my youth I used to see these types of maps in the old D&D modules and began to question their construction over the years. Unfortunately there wasn't anyone to ask back then. These days we have wonderful forums like these where I get to ask all those sorts of probing questions.
They are priests... Githyanki priests by the way.
But I had never questioned that before... Good thinking.