The hemicycle, now Room V of the Gregorian Egyptian Museum, was part of the former private apartment of Pope Pius IV in the Belvedere, built in 1562 to a design by Pirro Ligorio. In the years prior to the founding of the Gregorian Egyptian Museum in 1839, various Egyptian works present in the Vatican Museums collection were already located in the hemicycle.
The room also houses a number of large statues such as the so-called “Tuya of the Vatican” and the statues of Ptolemy II, his wife Arsinoë and his sister, Arsinoë-Drusilla.
A door-window in the centre of the route through the room opens onto the terrace of the Niche, which overlooks the Courtyard of the Pinecone. On the terrace there are various granite statutes of the goddess Sekhmet and three fragmented basalt sarcophagi.