Alpha v1.1.2_01 was the oldest Minecraft version where players could hear sounds and see their skins from 2010/2011.
As of March 8, 2018, the player cannot see player's skins in Minecraft versions up to Java Edition 1.6.4, which is caused by Mojang removing old game resources.
This was the last version to feature the old terrain generator along with the bright green grass, which was an iconic staple of Alpha.
In addition, due to the above, this was the last version in which the Far Lands would simply not render beyond 32,000,000 blocks out from the center of the map.
Gallery
Naturally generated arch.
An example of the local server in this version.
Mining through the block at the specific coordinates.
1.0