I came across a collection of maps called the Thiên hạ bản đồ tổng lục dại toàn (天下版圖總目錄大全). It contains a couple of maps which are just amazing.
This first one essentially places what we would today call East Asia within its astronomical context.
This map below, meanwhile, is of East Asia. It is interesting, among other things, to find that Korea (Choson) is rendered as an island.