When the server was created, Spawn was originally a plains and swamp biome. When walking out from 0 0 a few hundred blocks, you can still see parts of these biomes. However, everything within 300 blocks from spawn is terminally destroyed, and this destruction and griefing ripples out a few more hundred blocks.
A top-down view of spawn on day 1.
Spawn is typically considered to be the area within 1000 blocks from 0 0, and is littered with lavacasts. Some people gather at spawn to kill new players.
In late September, a platform made of cobblestone and other various materials appeared near max build height at spawn. The builder of this platform remains unknown.
A rendered image of spawn from the third of October.