Mediterranean cruises have been divided into two distinct groups: Eastern and Western. However, you may also want to take a look under Western Europe, as some cruises are difficult to easily put into Eastern or Western. Further, since there is no hard and fast definition of these two broad categories, it is a good idea to look at both anyway. Generally, Western Med cruises are a little more accessible for airfare, and some shorter durations can be had. Generally, if a cruise was not possible to categorise as either Eastern or Western, you will find it in Western Europe. Another set of itineraries to look at are the Iberian Peninsula ones listed under Western Europe.