I didn't write this because I'm a foreigner and not qualified in Indian History. I found these articles in internet stating that Adham Khan's octagonal tomb is symbol of a traitor for Mughal. So, please do correct me if the articles are wrong. If it is truth, it just makes me realise how much Akbar considered AK as a big traitor...Wow...
Article 1: Adham Khan's octagonal tomb is symbol of a traitor.
The Adham Khan tomb is octagonal in shape, something rarely seen in the architecture of the Mughal period. Octagonal tombs were in vogue during the Suri period and because of the relationship the Suris shared with the Mughal's, octagonal tombs became synonymous with traitors.
Therefore, it was only natural for Akbar to have commissioned an octagonal tomb for Adham Khan, seen no less a traitor than Sher Shah Suri.
Nevertheless, the tomb has certain interesting characteristic contrasts of this style in the form of the double dome and circular engaged columns that replace the corner buttresses.
The architecture of the tomb has an intricate setting of passages because of which it is often referred to as Bhul Bhulaiya - maze.
It has sadly seen a lot of vandalism and alterations over the years. Apart from its original use as the resting space for Adham Khan and Maham Anga, it has been used as a residence, police station and even as a dispensary during the British period.
As a result the tomb has been in constant use and a number of alterations have been made to the original structure, only Adham Khan's cenotaph can be found in the monument.
Maham Anga's gravestone is lost in the many changes that the tomb has seen.
Article 2 : Octagonal tombs and the Suri period.
Delhi, the capital of India, is dotted with the Muslim monuments, erected by Turkish Sultans, Khaljis, Tughlaqs, Lodhis, Sayyids and Mughals. The majority of these monuments are well-preserved. One such monument, which has been preserved by the Archaeological Survey of India, is that of Adham Khan. The tomb of Adham Kha is located in Mehrauli, a southwestern District of Delhi.
Adham Khan played a significant role in defeating the army of Baz Bahadur, the Sultan of Malwa, in the battle of Sarangpur in 1561. He was a trusted general of Akbar. However, he fell from the grace when he killed Ataga Khan, the prime minister of Akbar. This act of Adham Khan enraged Akbar and he ordered to punish Adham Khan. Accordingly, he was thrown down from the ramparts of the Agra fort. The sudden demise of Adham Khan made his mother, Maham Anga, mentally depressed. Soon after, she also died.
The tomb of Adham is believed to have been erected by Akbar. Maham Anga was also buried in the tomb of Adham Khan. The tomb of Adham Khan is an octagonal structure, a first octagonal tomb of Mughal period. The real prototypes were apparently the Tughlaq, Lodhi, Sayyid and Suri period tombs. The first octagonal tomb at Delhi, even in the whole India, was that of Khan-i- Jahan Tilangani, the prime minister of Firuz Shah Tughlaq, in a neighbourhood of Nizamuddin. This tomb provided a prototype to later royal tombs erected during the reigns of Sayyid, Lodhi and Suri rulers.
The tomb of Adham Khan is erected on a high octagonal platform. It is popularly known as bhul-bhalaiyan due to labyrinth maze inside. But, there is no such labyrinth maze inside; this is due to corridors and archways which give a bhul-bhulaiyan look and impression to the visitors.
Much of the plaster of the tomb has come off. However, one still finds stucco decoration on the interior and exterior of the tomb. The spandrels of all the arches are decorated with rosettes bearing the name of Allah, a decoration that can be seen in the tombs of Tughlaq, Sayyid, Lodhis and Suris. The three archways lead to the corridor and the main chamber of the tomb. The octagonal drum rests on the low dome which is crowned with an elegant finial.