There should be 6, but one is missing . . . 
(Hint!)Sorry about repeating myself - I didn't remember telling you before about the items.
There are 5 towns: Fountain Head, Baywatch, Wildabar, Swamptown, and Blistering Heights. They are linked by the Magic Mirrors, and you find the mirror code-names for each town in each town with the exception of Blistering Heights, whose code-name is given in Swamptown Caverns. Hopping between towns using the mirrors is a very convenient way of changing "continents", but you can't reach some of the continents via the towns without the Walk on Water spell.
There are some codewords for the mirrors that will get you to two of those "continents" but you aren't actually told about those until you reach the end-game. I can tell you what they are if you want, or you can play it straight. It's up to you.
There is also a Druid/Ranger spell "Nature's Gate" that will get you to one of the "continents" on the right day of the week. A word of warning, though, don't go to the Isle of Fire using that spell until your party is highly fire-resistant!
But it had proven to be too much for my party nevertheless.