No. 1 Reactor is a field map in Final Fantasy VII. It is the first dungeon in the game, one of two mako reactors in Midgar, and is explored only in the first chapter of the game, "No. 1 Reactor Bombing", with a party of Cloud and Barret. After this, the location cannot be revisited.
No. 1 Reactor is located on a walkway connecting Sector 1 and Sector 8. Past the entrance is an elevator which travels down to the main staircase, and ladders from the staircase lead down to the reactor core.
The No. 1 Reactor has a brown-ish tint, in contrast to the No. 5 Reactor which has an identical layout.
The entrance is a set of joined rooms with terminals. The doors are locked until opened by Biggs and Jessie respectively. At the northeast-most location, a dimly-lit elevator with a purple tint leads down to the lower areas, where on the first visit, a conversation with Barret takes place before descending.
An expansive room with a huge staircase leading down to the floor of the room. A tower atop the structure can be climbed with a ladder, but nothing of interest is located. At the bottom floor of the room, a door leads to the upper piping. A variety of enemies are encountered here in random encounters, including the MP, 1st Ray, Grunt, and Mono Drive.
In contrast to the main staircase of the No. 5 Reactor, the No. 1 Reactor has no pipe leading down from the door in the back-end of the room, which is instead unreachable.
The upper piping is filled with rusting, metallic pipes, and is reached through a door at the bottom of the main staircase room. At the end of this stone wall, a ladder across a huge pipe leads down to a set of beams suspended above the core's main room. Here, a Potion can be picked up before descending to lower piping.
The location of the Guard Scorpion boss fight, and where the bomb is set. The core comprises two screens: the walkway towards it with a save point and an inaccessible door, and the core itself. This is a large, tubular structure built into a wall, with "1998" written at the top, and a set of pipes leading to a valve at the bottom.
The reactor is visited during the game's first chapter, "No. 1 Reactor Bombing". It is unrevisitable.
|Entrance (after defeating Guard Scorpion)|
Various enemies are fought as random encounters within the Sector 1 Reactor, though most are dispatched with only one or two hits by Cloud or Barret, and deal little damage. The Sweeper, fought around the lower piping, is the most durable among them, which takes several hits to be defeated first. When encountered alongside other enemies, the smaller enemies should be defeated first to remove the damage they deal; otherwise, they are best dispatched by casting Bolt from Cloud.
The Guard Scorpion is fought as a boss in the core. This boss should be attacked by Cloud's Bolts while Barret uses normal attacks. When the Guard Scorpion raises its tail, it will counterattack until the tail is lowered. The player should either use Potions to heal in this time or simply avoid attacking until its tail is lowered, and then continue to damage it until it is destroyed.
|Potion x1||Entrance, upper piping|
|Assault Gun||Core (dropped by Guard Scorpion)|
A Potion is found in a treasure chest in the room on the southeast of the entrance, and another is found lying on the ground at the bottom end of the upper piping. By the reactor core, a Restore Materia can be picked up before reaching the core, and after defeating Guard Scorpion, the Assault Gun is obtained.
"Mako Reactor" plays inside the reactor itself until the Guard Scorpion battle begins, where the background theme changes back to "Opening - Bombing Mission".