True Borders of Korea

• Redesigned province shapes on the Korean Peninsula
• Adjusted terrain types on the Korean Peninsula
• Added decisions to implement the Eight Provinces System and to rename locations to more familiar names

The shape of Chungcheong-do in the vanilla game is truly strange and ugly. So, I started by fixing Chungcheong-do, which led to refining Gyeonggi-do, then Gangwon-do, Pyeongan-do, Hwanghae-do, and Hamgyeong-do. After also adjusting Gyeongsang-do and Jeolla-do, the shapes of almost all baronies on the Korean Peninsula have been modified.
Additionally, the vanilla map places many baronies in mountainous regions where few people live even today. I have addressed this by relocating them to areas that were historically more habitable and populous. Please refer to the table below for the changes in the number of baronies.
While perfect historical accuracy would be ideal, I utilized the best data available to me. I used the administrative divisions from the 1945 Liberation as a baseline (as county and township boundaries are typically based on natural features like mountains and rivers) and adjusted them to match the administrative districts of the Joseon Dynasty (prior to the administrative merger) and the borders of the Goryeo Dynasty.
Finally, I adjusted the shape of Yangju to ensure there is a barony representing what will eventually become Seoul (Hanyang).

Heightmap Adjustments

• Mount Baekdu, Mount Halla, Mount Jiri

Added Provinces

• Yeomju (Yeonan), Baeju (Baecheon), Papyeong, Suju (Bupyeong), Soseong (Incheon), and Gwaju (Gwacheon) in Hwanghae-do and Gyeonggi-do

Historical Borders & Travel Routes

• 867: Transferred the Duchy of Yukju from Silla to Balhae
• 1066: Transferred Bojuseong to the Liao Dynasty and implemented early Goryeo borders
• 1178: Implemented mid-Goryeo borders
• Implemented the Uiju Road and Mungyeong Saejae (Joryeong) routes (units will move along these paths)

Province Shape Adjustments

• Refined Chungcheong-do to look more authentic
• Realistically adjusted the shape of the Tumen River area
• Adjusted the estuaries of the Amnok(Yalu) River, Han River, and Daedong River
• And many more

Province Terrain Adjustments

• Farmlands: Gyeongju, Yangju (Namgyeong | Seoul), Hwangryeo (Yeoju, Gyeonggi), Yeomju
• Plains, Hills, Mountains
• Wetlands: Geumju (Gimhae, Gyeongnam), Jaeryeong (Jaeryeong, Hwanghae)

Province Shape Adjustments

Barony Count

Increased Barony Count

• Gyeongju | 3 → 4 | Gyeongju, Gyengsangbuk-do
  
• Yangju | 3 → 4 | Seoul
• Geumju | 2 → 3 | Kimhae, Gyeongsangnam-do
• Jeonju | 3 → 4 | Jeongju, Jeollabuk-do
• Chunju | 3 → 4 | Chuncheon, Hongcheon, Hoengseong, Yanggu, Hwacheon, Gangwon-do
• Sangju | 3 → 4 | Sangju, Mungyeong, Gyeongsangbuk-do
• Namgyeong | 3 → 4 | Hamheung, Heungnam, Hamju, Jeongpyeong, Sinheung, Hamgyeongnam-do

Decreased Barony Count

• Gaeseong | 4 → 3 |
• Seongju | 4 → 2 | Seongcheon, Yangdeok, Pyeongannam-do
• Deokju | 4 → 2 | Deokcheon, Maengsan, Yeongwon, Pyeongannam-do
• Chungju | 4 → 3 |
• Inje | 2 → 1 | in Chunju
• Hamyang | 4 → 2 | Change ‘Hapju(陜州)’
• Gyoju | 3 → 2 | Hoeyang, Kimhwa, Gangwon-do
• Wonju | 5 → 3 | Wonju, Pyeongchang, Yeongwol, Gangwon-do
• Deungju | 4 → 3 | Wonsan, Anbyeon, Muncheon, Hamgyeongnam-do
• Fengzhou4 | 2 → 1 | Hyesan, Gapsan, Samsu, Hamgyeongnam-do

• Seogyeong | → Pyeongyang | After 1066 ‘Seogyeong’
• Gyeongju | Forest→ Farmlands
• Jangdan | Farmlands → Hills (Cheolijeon)
• Tosan | Farmlands → Hills
• Geumju | Forest→ Wetlands
• And many more

Modified Rivers

• Geum River(금강)
• Nakdong River(낙동강)
• Duman River(Tumen)(두만강)
• Amnok River(Yalu)(압록강)
• Han River

Added Rivers

• Nam River (남강)
• Naeseong River (내성천)
• Neungseong River (능성강)
• Dokno River (독로강)
• Daeryeong River (대령강)
• Seongcheon River (성천강)
• Seomjin River (섬진강)
• Yeongsan River (영산강)
• Yeseong River (예성강)
• Jaseong River (자성강)
• Jaeryeong River (재령강)
• Cheongcheon River (청천강)
• Hyeongsan River (형산강)