The auguraculum (plural: auguracula), was a roofless temple oriented to the cardinal points, in which the priests of ancient Rome practiced augury and ornithomancy. The priest observer was positioned at the center of the temple, in a tent or a hut, and watched portions of the sky from which came the birds, which were marked out by stones placed along the perimeter of the temple. From this observation, the priest was believed to be able to predict the future.
The auguraculum was structurally a very simple device, a small thatched hut, which appears to have been regularly renewed.
Source: Auguraculum – Wikipedia