LAFAYETTE , 135 miles northwest of New Orleans on I-10, is geographically central in Cajun country, and is the key city for its oil business. Originally named Vermilionville, after the orangey bayou nearby, it was renamed in 1844 in honor of the Marquis de Lafayette. Today Lafayette is a quiet place, a city with a small-town feel and no real centre. It does, however, offer some lively Cajun history and good restaurants - and makes the best base for exploring the swamps, bayous and dance halls of the surrounding region.