The excavation of plentiful pottery deposits show that a village stood on the site and predates the temples themselves. This early pottery is dated to the Mġarr phase. Ta' Ħaġrat is built out of lower coralline limestone, the oldest exposed rock in the Maltese Islands. The complex contains two adjacent temples. The smaller temple abuts the major one on the northern side. The two parts are less regularly planned and smaller in size than many of the other neolithic temples in Malta. Unlike other megalithic temples in Malta no decorated blocks were discovered; however a number of artifacts were found. Perhaps most intriguing is a scale model of a temple, sculpted in globigerina limestone. The model is roofed and shows the typical structure of a Maltese temple including a trilithon façade, narrow-broad walling technique and upper layers of horizontal corbelling.
Major Temple
The Ġgantija phase temple is typically trefoil, with a concave façade opening onto a spacious semicircular forecourt. The façade contains a monumental doorway in the center and a bench at its base. Two steps lead up to the main entrance and a corridor flanked by upright megaliths of coralline limestone. The corridor leads into a central torba court, radiating three semi-circular chambers. These were partially walled off at some time in the Saflieni phase; pottery shards were recovered from the internal packing of this wall. The apses are constructed with roughly-hewn stone walls and have a rock floor. Corbelling visible on the walls of the apses suggest that the temple was roofed. A small sculptured temple was discovered here.
Minor Temple
The Saflieni phase temple rests to the north and is six and a half meters long. It is entered through the eastern apse of the larger temple. Smaller stones have been used in its construction and it exhibits irregularities in design considered archaic or provincial.
Excavation
The site was excavated between 1923 and 1926 by SirTemi Zammit, then Director of Museums. The site was again excavated by John Davies Evans in 1954, and British archaeologist David H. Trump accurately dated the complex in the 1961 excavation. The temple was included on the Antiquities List of 1925.
Restoration
Parts of the façade and doorway were reconstructed in 1937.