As with any usual Minecraft server, Purity Vanilla has several portals to the End scattered about the overworld.
One commonly known stronghold is the one nearest to spawn, which has been thoroughly explored and mined out.
Players often leave their own mark in the End Portal chambers of strongholds through the usage of signs informing others of their visits, or the placement and destruction of blocks.
Using his superior engineering skills, noob_24 calculated the location of 38 out of the world's total 128 strongholds, with an accuracy of approximately 200-2000 blocks. These locations are written here on the wiki for the public to use, making the end more accessible, but do keep in mind that due to seed changes many of these locations may not have strongholds.
Many bases have been built around end portals however their longevity is never long lasting. Due to the fact that there were many seed changes and chunk reloads, abnormalities mean that there can be more or less end portals existent on Purity than on a regular vanilla world. Surrounding areas of spawn region end portals are nearly always completely decimated, with towering casts and waterlogged structures making the job of locating the portal itself hard, however the portal itself if always there due to the rule making the destruction/removal of end portals themselves bannable.
End portal coords that are confirmed and the closest to spawn are -1982, -266, a lavacasted tower amidst the large greater spawn ocean.