The Monument to Ahmad is a public sculpture created by Mohamad in honour of his brother Ahmad. It was installed in the city square of Abadan, Iran, on June 20th, 1980. The sculpture measures 140 centimetres in height, 100 centimetres in length, and 50 centimetres in width. It rests on a base that is 74 centimetres tall and roughly the same length and width as the sculpture itself. The entire monument stands 214 centimetres tall from the ground, including the base. The sculpture was crafted from locally polished concrete, while the marble base was imported from Carrara. The base extends 74 centimetres below ground level. During installation, Mohamad requested to keep the excavated soil to allow the marble base to be placed half below ground.

The sculpture was in the shape of a figure of a man. His posture was upright and contrapposto, with his gaze slightly directed upwards. The sculpture faced true north (Mohamad had always hoped that one day he would see the aurora borealis; this is confirmed by his several works coloured with bright fluorescent green paint).

It is now known that the concrete structure was assembled from 26 separate concrete-cast pieces. The sculpture was originally carved from soft wax and then divided into smaller sections suitable for casting. The sculptor reused wax from another series of 26 sculptures he created in the same year. He had made 22 models of airplanes, trains, blimps, cars, and even a pencil sharpener, all in a formal style reminiscent of Italian Futurism. He also made four small sculptures in the same series, depicting a lanky plant with white and yellow flowers. The wax he used was salvaged from a few boxes of unused paraffin candles taken from a European embassy looted during the revolution and given to Mohamad on his birthday.

On May 8th, 1984, a structural engineer observing the facade of a nearby building noticed the Monument to Ahmad and grew fond of the sculpture. When he approached it for a closer look, he saw the surface details. It looked like parts of the sculpture were made up of tiny dimples similar to those on a golf ball. After further inspection, he noted that they mainly appeared on the north side of the sculpture, on the torso, eyes, cheeks, and left leg. He naively guessed that they resulted from erosion. Moved by the figure's resemblance to a lost friend, the engineer decided to fill in the small circular indentations with black putty to smooth the surface, using materials he had on hand from that day’s work.

The next day, the engineer returned and was surprised to find an empty marble base with the sculpture 'Monument to Ahmad' missing. He asked around and located the sculpture 20 km north of the site in a deserted plain. The sculpture was leaning on its left leg, angled 45 degrees from the ground, with the torso and head facing forward. Its shadow pointed to a small green rock at the base of a small seedling growing nearby. The engineer notified officials, who retrieved the sculpture and urged that it be properly secured at its base. The engineer even criticised city officials for using the city’s budget to import such a grand piece of foreign marble without adequately anchoring it to the sculpture.

On August 17, 1997, the engineer revisited Abadan and noticed that the sculpture and the base were no longer there. Only the hole in the city square remained, filled with trash blown in by the wind. Out of curiosity, he asked around, and no one knew what had happened to the sculpture or the sculptor; some speculated that Mohamad had gone abroad, while others said he had passed away. The engineer thought that the sculpture might have been destroyed during the Iran-Iraq war, and the marble base was probably taken by someone seeking use as building material. He learned that the city officials were embarrassed by the disappearance and promptly secured the concrete structure to its marble base when they rediscovered it. To his shock, the very night the sculpture was returned to the city square and properly secured, it disappeared again. The engineer returned to the site, where he found the missing sculpture. Not surprisingly, neither the sculpture nor the base could be found; only a large bush of plants, later identified as Peganum Harmala (or Syrian Rue), was growing at the site. While examining the plants, he rediscovered a small green rock he had noticed earlier; he picked it up and put it in his pocket.  

It is sometimes speculated that, following these events, when Mohamad heard the news, he brought the soil he had kept from the excavation and filled the empty hole.

On June 21, 2039, the sculpture, including its marble base, reappeared in the city square.