由于缺乏农业或工业所需的空间，三个现代城邦的经济依赖于贸易或旅游业。 例如，新加坡拥有世界上第二繁忙的海港，摩纳哥和梵蒂冈城是世界上最受欢迎的旅游目的地之一。 虽然几个非主权城市，如香港和澳门，以及阿拉伯联合酋长国的迪拜和阿布扎比，有时被视为城邦，但它们实际上是自治区。 大多数地理学家和政治学家都认为，这三个现代真正的城邦都是摩纳哥，新加坡和梵蒂冈城。
新加坡国立大学建筑Assignment代写：旅游目的地
The economy of the three modern city-states depends on trade or tourism because of the lack of space needed for agriculture or industry. For example, Singapore has the second busiest port in the world, and Monaco and Vatican City are among the most popular tourist destinations in the world. Although several non-sovereign cities, such as Hong Kong and Macau, and Dubai and Abu Dhabi in the United Arab Emirates, are sometimes regarded as city-states, they are actually autonomous regions. Most geographers and political scientists agree that these three modern real city-states are Monaco, Singapore and the Vatican City.