How do I get to the merchants sector?

When I open the map of Krondor, there are several sections that will not "light up" when I move the cursor over them. I assume one of these is the merchant sector. Can someone tell me how to get into these sectors (in particular, the merchant sector)?

Thanks.

Not all of the map lights up. There are only seven sectors you can access during the game - North Gate, Sea Gate, Palace, Poor Quarter and three of which I don't remeber exact names: one with Rainbow Parrot, Ye Bitten Dog and Wealthy sector (one with merchants). That last one is the smallest one, just north of the Palace.