Gandhinagar, Jan 8 (IANS): Prime Minister Narendra Modi Thursday morning inaugurated the Salt Mountain, a memorial dedicated to Mahatma Gandhi, built near the Mahatma Mandir complex here, the venue of the 13th Pravasi Bharatiya Divas (PBD).

Modi went around the exhibits related to Gandhi's life at the Gandhi Kutir and also wrote on the visitor's book.

The inauguration comes ahead of the formal inauguration of the official part of the PBD.

More than 4,000 delegates have arrived for the 13th PBD, the world's largest annual gathering of people of Indian origin aimed at enhancing networking and reinforcing commercial linkages.

There are 25 million people of Indian origin residing outside India.

The event is being held in Gandhinagar Jan 7-9 to mark the centenary of India's "sarva sreshtha pravasi Bharatiya", or foremost Indian diaspora member, Mahatma Gandhi's return to the country from South Africa.

The Mahatma Mandir is a sprawling complex spread across 60,000 sq mt.