The Pyramid of Cestius is an imposing pyramid-shaped tomb in Egyptian style built between 18 and 12 BC, erected at the behest of Gaius Cestius, praetor, tribune of the plebs, and member of the College of the Septemviri Epulones, magistrates responsible for organizing sacred banquets in honor of the most important deities. Gaius Cestius expressly provided in his will that his heirs were to erect the pyramidal tomb for him within 330 days, under penalty of losing his rich inheritance, as recalled by the inscription on the eastern facade of the monument: "opus absolutum ex testamento diebus CCCXXX, arbitratu (L.) Ponti P. f. Cla(udia tribu), Melae heredis et Pothi l(iberti)". The monument was built in the required time, between 18 and 12 BC.

Made of concrete and clad in Carrara marble slabs, it is 36.40 meters high with a square base measuring approximately 30 meters on each side. The structural strength of the concrete allowed the Roman pyramid to be built with a much more acute angle than the Egyptian ones. After the conquest of Egypt in 31 BC by Augustus, Egyptian culture inspired Roman culture: the Pyramid of Cestius is the only surviving example of its kind in Rome.
The Pyramid was incorporated into the Aurelian Walls during their construction, between 271 and 275 AD, an intervention that helped preserve its structure over time.
Inside is The burial chamber, approximately 23 m2, features a barrel vault and walls decorated with refined frescoes on a light background depicting nymphs and winged Victories.