Corfu old town is an amazing place full of neoclassical buildings and traditional alleys. Some years ago, Corfu was inscribed on UNESCO world heritage center listListon Square is the central square of Corfu. All the buildings have venetian style of architecture. You can find a lot of cafeterias, always full of people and a lot of restaurants around the square. Corfu town has tow fortresses, the old and the new, as the locals use to call. Both of them  are nice and the view is amazing.
Between the city and the castle is the Spianada square, wich is is the largest square in Greece. So as you come to make your vacations in Corfu you have to visit the old town and spend a half-day or an evening walking through this place.