The antechamber of Anak Tomb No. 3 is considered to be the equivalent to the front yard of a house. Guards carrying a sunshade, Jeol (ceremonial flag featuring pompons), banners, and axes can be seen on the southern wall of the antechamber (east of threshold) as if to courteously greet the incoming royalty. A ceremonial band is depicted on the southern wall west of the threshold, cheerfully playing music as if a grand festival was taking place in the yard. The Subak (ancient Korean martial art) exhibition on the eastern section of the southern antechamber wall adds to the festive atmosphere. The western auxiliary chamber, correlating to an outbuilding or guest room of a house, features a portrait of the deceased conducting government affairs while his wife looks on affectionately from the adjacent wall. Two Royal Guards, depicted on either side of the western auxiliary chamber threshold, stand guard and protect the noble couple. Across the antechamber from the western auxiliary chamber, a glimpse of residential life can be witnessed inside the eastern auxiliary chamber through depictions of a kitchen, mill, meat storehouse, carriage house, and horse stable.
The ceiling of the long, rectangular antechamber was constructed with parallel triangular supporting stones, and an image of a blooming red lotus can be seen in the center.