IAA Headquarters

The IAA (International Affairs Agency) Headquarters is a skyscraper in Grand Theft Auto V and Grand Theft Auto Online. It is the IAA's field office for the state of San Andreas.

Overview
The building is located on the corner of Power Street and Swiss Street in Pillbox Hill, Downtown Los Santos, right next to the Federal Investigation Bureau Headquarters. The skyscraper is the third tallest structure in Los Santos after the Maze Bank Tower and the Mile High Club, and is almost identical in height to the FIB Headquarters.

It is based on the Two California Plaza, a 751-foot (229 m) skyscraper in Los Angeles, California.

Design
The IAA and FIB buildings are both government run agencies and are similar in design both in the interior and exterior of each skyscraper. The building has a total of 53 floors and most likely possesses similar features to the FIB building, such as restricted and high-security areas in the highest floors. The rest of the building is most likely made up of offices. A large number of offices can be seen in Three's Company, as well as the 36th floor, which has a "Legal Affairs" section and a few offices.

Events of Grand Theft Auto V
Part of the inside of the building (36th floor) is seen in the mission Three's Company, where Michael De Santa, Trevor Philips and Franklin Clinton are forced by FIB agent Steve Haines to perform an abduction against the IAA in order to boost the funding for the FIB. During the abduction, Karen Daniels is seen torturing and beating Ferdinand Kerimov, which implies she is working for the agency as a lead interrogator.

One of the 15 Knife Flights needed to attain 100% Completion needs to be performed between the IAA Headquarters and the FIB Headquarters.

Events of Grand Theft Auto Online
The IAA facility is infiltrated during the The Agency Deal. Miguel Madrazo enlists KDJ's help to broker a deal with a crystal vape dealer. However, the dealer betrayed them and sold the formula to the IAA instead.

As a result, the players infiltrate the facility and takes out the oncoming IAA agents in order to get to the dealer. The players will then interrogate the dealer for the location of the recipe. Once the dealer gives up the location of the recipe, the players will face off against more IAA agents on the way out of the facility before fleeing via the Pillbox North Station.

Glitches

 * It is possible to glitch inside the building. One has to parachute from high altitude then head for the second window (from right to left) of the 36th floor as seen on this video. The player should go through it and land in the building. One can notice that most of the floor is poorly designed (except the office where Mr. K is tortured). Some walls are invisible and going through it will make the player fall "inside" the building and teleport to a nearby street.
 * This bug was patched in the enhanced version. However, there is still a way to get into the building if the player replays Three's Company and fails the mission somehow while Michael is still grappling off the side of the building, after what the player must then exit the mission. Once outside the mission, follow the steps of the original glitch. The player should be able to parachute through the window now.
 * Another way to get inside the building is to jump and ragdoll through a non-solid wall on the top of the building, as seen here. The player will enter Blue Hell and can parachute to the location of the solid interior, which will be invisible. Ragdolling or going into first person will cause the interior to appear.
 * This glitch has been patched in GTA Online. If the player manages to fall through the non-solid wall, they will immediately die and respawn on the street below.

Trivia

 * Only the floor where the break-in from the mission is seen; the rest of the building is inaccessible.
 * For an unknown reason, one row of windows on the lower section of the south side of the building is not solid and can be flown through, as seen in this video.