To the world of today the men of medieval Christendom already seem remote and unfamiliar. Their names and deeds are recorded in our history-books, their monuments still adorn our cities, but our kinship with them is a thing unreal, which costs an effort of imagination. How much more must this apply to the great Islamic civilization, that stood over against medieval Europe, menacing its existence and yet linked to it by a hundred ties that even war and fear could not sever. Its monuments too abide, for those who may have the fortunate to visit them, but its men and manners are to most of us utterly unknown, or dimly conceived in the romantic image of the Arabian Nights. Even for the specialist it is difficult to reconstruct their lives and see them as they were. Histories and biographies there are in quantity, but the historians for all their picturesque details, seldom show the ability to select the essential and to give their figures that touch of the intimate which makes them live again for the reader. It is in this faculty that Ibn Battuta excels.
This article (originally from Muslim Technologist, March 1990, but no longer available online) says
Ibn Battuta was the only medieval traveller who is known to have visited the lands of every Muslim ruler of his time. He also travelled in Ceylon (present Sri Lanka), China and Byzantium and South Russia. The mere extent of his travels is estimated at no less than 75,000 miles, a figure which is not likely to have been surpassed before the age of steam.
A public domain edition of Encyclopedia Brittanica has a narrative outline of the journey. There's a documentary travelogue
in which Tim Mackintosh-Smith follows in the footsteps of 14th Century Moroccan scholar Ibn Battutah, who covered 75,000 miles, 40 countries and three continents in a 30-year odysseyYou can watch the 1st part of that documentary online via youtube: