The hollows were dug out at southwest and northeast ends of position No. 7 of the Phyodae archaeological site. The hollow in the southwest place is called No. 1 and that in the northeast place is called No. 2.

Hollow No. 1 is 1.5 to 2 meters in diameter and 35 centimeters in depth. The inclination angle of its wall is some 40 degrees.

Unearthed in the hollow were pieces of patterned vessels, grinding stone and net sinker tantamount to nearly 45 items.

Most of the patterned vessel pieces have patterns of fir leaves. Among them are pieces of vessels with short oblique line patterns and a piece of vessel with lightning pattern.

Hollow No. 2 is nearly circle whose diameter is about 3 meters and depth is about 0.5 meter in the center.

Excavated in the hollow were pieces of 500-600 earthenware, hammer, foundation of grinding stone, polishing stone, axe, arrowhead and net sinker and large pieces of charcoal.

The newly discovered hollows are precious ones for the study of the cultured community life of people in the Pyongyang area during the Neolithic era.