Suakin, one of the oldest seaports in Africa, was used by African Muslims who set out for pilgrimage to Saudi Arabia.
After visiting the island, Erdoğan said earlier on the same day that the island needs rebuilding and called for a restoration process during a speech in the University of Khartoum, where he was awarded an honorary doctorate.
During his two-day official visit to the country, he visited several Ottoman sites including Al-Hanafi Mosque, Al-Shafei Mosque and an old customs building.
Ottomans used the port city to secure the Hejaz province -- present-day western Saudi Arabia -- from attackers using the Red Sea front.
Erdoğan's visit, the first by a Turkish president, was welcomed by his Sudanese counterpart Omar al-Bashir who said it would boost relations between the two countries.