This 3yr old peninsula map seed still works!
I posted this seed 3 years ago (https://www.reddit.com/r/FarthestFrontier/s/YHda9IehIs) and decided to see whether it still works - if anything, it's even better now. There are only 2 access points - the northern one is wide but has a hill giving a good vantage point for towers, while the south is a double choke-point. There's also far more room for a decent-sized town. Downsides: only a medium map, and most of it is covered in water.
Seed: 68E6AD687D2 - Type: Random - Size: Medium
Northern access with hill for fortification
Super-professional blow-up of the mini-map showing water areas
PS a lot of innocent villagers died in the making of this post