Big House

The Big House is a large sky-blue house which serves as the main administrative building at Camp Half-Blood. Mr. D, Chiron, and the other Camp Half-Blood staff members meet with the cabin counselors there. Also, it serves its purpose as the camp's infirmary, which is needed quite often. There are four floors including a basement and an attic in the Big House. It is home to Mr. D, Chiron, and Argus.

History
The Big House has been a part of Camp Half-Blood for a long time. It has held the Oracle's body ever since she died (before Rachel was made the Oracle in The Last Olympian. It was painted red during the 1980s' through the early 1990s', but has since been painted baby-blue with a white trim. It also has a bronze eagle weather vane with wind chimes that turn into dryads as they spin.

Infirmary
Wounded Greek demigods would usually go here for treatment or healing. Most likely demigods from the Apollo cabin help out, because their father, Apollo, is the god of healing. But Argus also helps out in the Infirmary. In The Lightning Thief movie, there is an infirmary but no mention of a Big House is made. In The Lost Hero, Piper McLean woke up in the infirmary after fainting in Hera's cabin.

Attic
The attic is the home of many things. It holds many trophies that demigods have taken from monsters and other situations, such as quests that demigods have taken. The attic used to hold the Oracle's body (or what was left of it), which told prophecies for the quests of the campers, but since the Oracle was replaced by Rachel Elizabeth Dare, prophecies are now told in a nearby cave. Or, like in The Lost Hero, if Rachel would suddenly black-out into a prophecy, the campers would place her on a stool.

Deck
This is where Chiron and Dionysus play Pinochle most of the time. It is furnished with lawn chairs and tables, like a vacation home. Lawn chairs are occasionally upgraded with pillows and a blanket to help ease a wounded (or recovering) demigod. The deck wraps around the Big House's entire perimeter, giving an excellent view of the Long Island Sound and Camp Half-Blood's immense forest.

Chiron's Office and Apartment
Chiron has his room and does official business from his desk in his office. It has a record-player and a full-screen video (where the orientation film watched by all new campers is located). He also has a boom-box (with the most horrible music from Italy with a bunch of violins and some guys singing opera in Italian), which was used by Annabeth Chase and Percy Jackson to scare away the Stymphalian Birds. Chiron's apartment is also located here as he lives and also gives training to Percy and other demigods at Camp.

Rec Room
This is the room that Chiron holds all of the head of cabin meetings, as seen in The Titan's Curse and The Lost Hero. It also has a ping-pong table, as that is the "table" that the meetings are held around.

Basement
The only mention of the basement is when Chris Rodriguez was taken care of in The Battle of the Labyrinth by Clarisse La Rue. Chris Rodriguez was driven insane by King Minos in the Labyrinth, and Clarisse was attempting to calm him. The basement is a storage space for stockpiled ambrosia and strawberry preserves.

Trivia

 * The Big House is described sky-blue, but is brown in The Lightning Thief (graphic novel).