一本用意大利方言写的《光明之城》，记录了一个冒险的航海者在700年前航行了上万公里，来到中国的一个城市的所见所闻。在这个西方旅行者的笔下，这座城市被称作“刺桐”或“光明之城”，光明之城是指这个城市的繁华，连晚上都灯火通明。这到底是中国的哪座古城，在中古时期这样著名呢？

The book《The City of Brightness》written in Italian dialect has recorded what a western navigator saw and heard about a city in China by 700 years ago. The city was named "citong" or "the city of brightness”. It meant that the city was very prosperous and even at nights there were myriad lights on. Which city does it refer to? Why was it so famous in the mediaeval times?