Abu Ghurob (Abu Ghurab) is the modern name for a site about 1km to the north of Abusir, situated on the west bank of the Nile between Giza and Saqqara. Several Old Kingdom rulers built their pyramid complexes at Abusir, but it became a custom during Dynasty V for pharaohs to dedicate separate temples to the Heliopolitan sun-god Re, in addition to the construction of their pyramids. At Abu Ghurob there are remains of two sun-temples built by Userkhaf and Niuserre of Dynasty V, although the Abusir Papyri documents the names of six temples. The sun-temples have recently been opened to the public.

The site was excavated at the beginning of the 20th century by German scholars Borchardt, Schaeffer and von Bissing and studied in the 1950s by the Swiss Institute directed by H Ricke.

Userkaf, the first king of Dynasty V built his pyramid complex at North Saqqara and was the first king to build a royal monument at Abusir, his sun-temple at Abu Ghurob, which he named 'Nekhen-Re' (Stronghold of Re). Swiss archaeologists suggest that the temple in its earliest form may have been connected to the goddess Nekhen, or the goddess Neith, perhaps representing the original mythological mound surmounted by a mast (the obelisk) or to promote the unification of the country by means of the sun religion. Today only traces of his temple remain on a promontory on the edge of the desert and there were no inscriptions found giving clues to its original purpose or the choice of its location. What research has ascertained is that the temple was built in four successive stages with additions by later kings, Neferirkare and Niuserre.

So little remains of the temple that only a few fragmentary architectural elements were found, which included parts of a short granite obelisk which would have been placed on a pedestal building in the centre of the temple (replacing the original symbolic mound) and probably added during a later stage of reconstruction. Later still the structure was enclosed, an altar constructed in front of the obelisk and chambers added to the sides of the building. Userkaf's reign was short (about 7 years) and it is thought that his temple was unfinished at the time of his death and added to by his successors in his name. During excavations a beautiful schist head was found from a statue of Userkaf, wearing the red crown (now in Cairo Museum).

Userkaf's sun-temple had a causeway which was divided into three lanes along its length by low mudbrick walls with the widest lane in the centre and it has been suggested that animals may have been driven along the lanes towards their ritual slaughter. Although the sun-temple is oriented east to west, the causeway was offset towards the north-east and a valley temple. Some archaeologists suggest that the causeway was pointing in the general direction of Heliopolis and may indicate a solar or astronomical purpose.

The valley temple was also badly destroyed when Ricke investigated it, but a plan was reconstructed from fragments, suggesting it to have been quite an elaborate structure including an open courtyard surrounded by a portico with five (or seven) niches or chapels at the rear.

Userkaf's successor Sahure was the first monarch to site his pyramid at Abusir, but there has so far been no sun-temple found at Abu Ghurob in his name. The only other remains of a sun-temple belongs to Niuserre, the sixth king of Dynasty V, which is located about 500m north-west of Userkaf's temple. This monument was known to early travellers as the pyramid of 'Righa', but was first excavated by Borchardt and Schaeffer's German archaeological expedition between 1898 and 1902. Niuserre's sun-temple, which was named 'Delight of Re', is much better preserved than that of Userkaf and many fragments of relief decoration were recovered, some depicting the heb-sed festival (now in Berlin Museum).

Niuserre used similar elements in the construction of his sun-temple as those reconstructed from Userkaf's monument and which had become common in pyramid complexes. The upper temple was on a levelled terrace, its rectangular walls first constructed in mudbrick and later encased in yellow limestone. A vestibule led into a courtyard which was dominated on its western side by a large obelisk constructed from limestone blocks and which stood on a flat-topped pyramid-shaped pedestal, around 15m high. The obelisk probably symbolised the 'ben-ben' stone on which the sun's rays first shone in the Heliopolitan creation myth.

In front of the pedestal stood a large and beautiful altar, 6m in diameter, which was constructed from five blocks of white alabaster. This was carved in deep relief with a circle at its centre and four 'hotep' symbols on the sides (the hieroglyphic sign representing 'offerings', 'peace' or 'satisfied'). This beautiful altar still remains in situ. On the southern side of the obelisk was a chapel which contained the 'Chamber of the Seasons', its reliefs depicting the procreating force of the sun-god in nature. Unfortunately a number of these reliefs in Museums in Germany were destroyed during the Second World War. At the north-east corner of the enclosure is a series of ten alabaster basins (nine still surviving) thought to be used in sacrificial rites, either for water or blood. Outside the upper temple enclosure walls (which contained storehouses), a boat-shaped pit lined with mudbricks can still be seen on the southern side and which is another reminder of the elements of the pyramid complex.

The causeway descended steeply from the walls of the terrace and like Userkaf's causeway was offset to the north-east and the valley temple which formed an entrance pylon to the complex. The scant remains of the valley temple are in boggy ground and have never been properly investigated, but its thick enclosure walls led Borchardt to believe that they were the walls of a settlement.

The purpose of the sun-temples has never really been satisfactorily explained and suggestions for their significance are numerous. What they do seem to symbolise is the union of the king with the solar deity, which had become almost a state god during this period. At least by mid-Dynasty V they seem to have had a close connection to the pyramids at Abusir, although we know that the temples had their own donations, lands and maintenance staff.