What city did the English explorer Sir Richard Francis Burton visit in 1853 disguised as a Muslim merchant?

Sir Richard Francis Burton (19 March 1821 – 20 October 1890) was an English explorer, geographer, translator, writer, soldier, orientalist, cartographer, ethnologist, spy, linguist, poet, fencer, and diplomat.

Burton's first explorations and journey to Mecca got the approval of the Royal Geographical Society for an exploration of the area. His seven years in India gave Burton a familiarity with the customs and behaviour of Muslims and prepared him to attempt a Hajj (pilgrimage to Mecca and, in this case, Medina). It was this journey, undertaken in 1853, which first made Burton famous. He had planned it whilst traveling disguised as a Muslim merchant among the Muslims of Sindh, and had laboriously prepared for the adventure by study and practice.

Burton was certainly not the first non-Muslim European to make the Hajj but his pilgrimage is the most famous and the best documented of the time. He adopted various disguises including that of a Pashtun to account for any oddities in speech, but he still had to demonstrate an understanding of intricate Islamic traditions, and a familiarity with the minutiae of Eastern manners and etiquette. Burton's trek to Mecca was dangerous, and his caravan was attacked by bandits (a common experience at the time). The pilgrimage entitled him to the title of Hajji and to wear the green head wrap. Burton's own account of his journey is given in A Personal Narrative of a Pilgrimage to Al-Madinah and Meccah (1855).