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.
As a brief reminder from the Wiki staff, we advise that you always look over this list when you're about to go to the end and also try spread information about portals so some locations are more accessible- good luck and happy end raiding.