Minecraft 1.8 marks the end of an era. It was the final major update before the combat overhaul (1.9), the shift to a more "adventure" focus, and Microsoft's acquisition of Mojang (which completed just two months after 1.8's release). For builders, it offered elegance; for engineers, slime blocks; for PvPers, a timeless meta; and for mapmakers, a command revolution.
Invisible, indestructible blocks used to create boundaries in adventure maps. Custom World Type: minecraft version 1.8