Version 1.5.2 represents the polished, stable conclusion of this era. It was a time when the Nether was simpler (no ancient debris or piglin bartering), the combat was the classic "click-spam" style (no 1.9 attack cooldowns), and the End was a barren wasteland with little to do beyond slaying the Dragon.
Installing a world download in version 1.5.2 is straightforward. Minecraft 1.5.2 Maps 1.5.2 world download
When a server shut down, its world file was often lost forever. However, many admins uploaded their final server saves to the Internet Archive. Search for "Server save 1.5.2" or "1.5.2 world file" on Archive.org. These are often the most valuable finds because they contain player-built cities, not just curated challenge maps. Version 1