The Gullopolis Villager Breeder, Carrot Farm, and Honey Farm
A big piece of my goal for a city is a villager trading hall for ultimate item grinding, PARTICULARLY librarians for enchantments. To do this, we need a villager breeder. I am using ImpulseSV's design (https://www.youtube.com/watch?v=VTseLpa9Iyc), though even since 1.16 it has to be heavily modified (and still doesn't fully work). Additionally, in order to grow the carrots faster AND get honey, I built a spidery honey farm over the top based on 8 instances of Wattles' design here: https://www.youtube.com/watch?v=lmGs-7y7G3M
This has been through a million iterations for a few reasons. First, I had to reroute the pistons to refill the bottles in the dispensers so they didn't lock with the red stone. Wattles design uses locking hoppers with 4,4,5,5 items, and that doesn't work...it has to be 1,1,1,1 for the non-filter items. I battled getting the villagers to breed...first I need an airspace for stuck bees to come back into the chamber, then I need to solve villager mgmt. Sometimes a baby gets into the farm, grows up, and essentially stops the breeder (since the all 4 beds are occupied). I need to carefully slaughter that guy. Also, if the trapdoors are placed wrong, the villagers can't path find to the bed so breeding doesn't happen...which is terrible since then the villagers eat ALL the carrots and I get none.
In the end I got it working, but I'm constantly iterating to get the villager escape problem solved in a better way. For now it works well enough and I got plenty of villagers and continue to get tons of honey and carrots.