Barack Obama and wife Michelle are guided by a senior ASI official at Humayun’s tomb in Delhi on Sunday. (AP)

New Delhi, Nov. 7: President Barack Obama had a question soon after he reached Humayun’s tomb this afternoon: “How is this monument different from Taj?”

“Taj Mahal was modelled on Humayun’s tomb and the building style inspired the Taj, which was built 70 years after this monument,” replied K.K. Mohammed, the superintendent of the Archaeological Survey of India in Delhi.

“But the height of this monument is 167 feet while that of the Taj is 243 feet,”he added, before explaining how the first garden tomb in the subcontinent was commissioned in 1562 (and completed in seven years) by Humayun’s widow Hamida Banu and designed by Persian architect Mirak Mirza Ghiyath.

“It’s wonderful,” said Obama, striding down to the tomb with wife Michelle. The US President was turned out in a white shirt and black trousers while the First Lady wore a turquoise dress.

They are not visiting the Taj.

Mohammed, in awe after meeting the “most powerful man in the world”, said: “Obama asked me about the architectural strands that had gone into the building of this monument while Michelle was keen to know what kinds of stones were used in it.”

Obama also asked about Dara Shikoh, the eldest son of Shah Jahan who was murdered on brother Aurangzeb’s orders and buried in an unmarked grave on the premises. He is believed to have had an influence over American transcendentalists.

After going around the tomb, the couple walked to the courtyard where 14 children — between 5 and 13 years — were waiting. As soon as they saw the Obamas approaching, the children of workers at the monument greeted them with “namaste”.

“Welcome Obama uncle…,” chanted the six girls and eight boys, wearing new uniforms given by the ASI. The children are students of a school run by the Archaeological Survey of India.

The couple responded by waving, smiling and shaking hands before going on to chat with the help of an interpreter. “Where do you study?” the President asked the children.

Later, he and Michelle distributed gifts — a silver bookmark with the presidential seal and Obama’s signature — among the children, six workers and a teacher.

“He asked my name and shook hands with me. He also gave me a gift,” said Babu, 10, whose father is a labourer at the tomb, adding he had said “thank you” for the gift.

Asked if he knew who had given him the gift, Babu said: “Our teacher told us that he is from America.”

Eight-year-old Usha was trying hard to figure out what she could do with the bookmark. “Yeh chandi ka hai (This is made of silver),” she finally said. “I will give it to my mother and she will be very happy.”

The Obamas were at the tomb for 40 minutes. “Through the rise and fall of empires, Indian civilisation has endured and led the world to new heights of achievement. The world owes a profound debt to India and its people,” the President wrote in the visitors’ book. Michelle signed below his signature.

Around 5.30pm, their motorcade dashed through emptied streets to the hotel for a short break before the dinner with Prime Minister Manmohan Singh and his wife Gursharan Kaur.