El Presidio

El Presidio (or The Prison) is a location featured in Red Dead Redemption and is fort who serves as a Mexican Army stronghold located in the Diez Coronas region of the Nuevo Paraiso territory.

Red Dead Redemption
A large portion of the Luisa Fortuna mission "Must a Saviour Die?" takes place in this location and, naturally, the Abraham Reyes mission "The Gates of El Presidio" takes place here.

Undead Nightmare
During the Undead Nightmare,  is a Safe Zone protected by high walls, multiple cannons and the Mexican Army. Ladders have been added to certain points on the walls for ingress and egress. There is a perpetual horde of zombies surrounding the fort. It is also one of two(fort mercer) locations that the Missing Persons activity is linked.

Amenities
Wanted Poster

Trivia

 * It is a common location in multiplayer to become public enemies or stage large gang wars, most likely because of the many cannons and Gatling guns.
 * It is possible to see El Presidio from the top of Nekoti rock, though it looks like an undetailed block. To do this, binoculars or a sniper scope are required.
 * In multiplayer, if a player took control of a mounted weapon and fired at the walls of El Presidio, an additional $20 will be added to their bounty. This can be a very useful tactic for any players wanting to complete any challenges or achievements/trophies.
 * In Undead Nightmare El Presidio is a safe zone, the doors are locked and there are ladders around the side. Strangely though, one or two zombies can get in somehow, and will attack the settlers, sometimes killing them. This obviously shouldn't happen as it's a safe zone, and may be some kind of glitch.
 * In Undead Nightmare, the Undead spawn en masse outside the front gate. Man one of the cannons near the gate and you can score the Mowing Them Down achievement/trophy by mowing them down three and four at a time. The other kill-based achievements (Long Arm of Marston, Rain of Bullets, and the headshot achievement) are also easily scored there, given enough ammo and patience.
 * This is the perfect location to obtain Undead Sharpshooter Rank 4, in which the player must kill all four Undead types in one Dead Eye meter. Conveniently, all four types continually respawn near the gates.
 * It seems that at least one person in El Presidio may become hostile towards John Marston for no reason.
 * In Multiplayer, shooting TNT or Lanterns inside El Presidio will result in a $20 bounty. Throwing Dynamite or a Fire bottle will also result in a bounty if the explosion/fire touches any part of the fort.

Red Dead Redemption
The discovery of locations in Red Dead Redemption count towards the following Trophies/Achievements:

Use of the mounted weapons available at  can contribute toward the following Achievement/Trophy:

Undead Nightmare
Keeping this location free of Undead infestation during the Undead Nightmare contributes toward the following Trophies/Achievements: