During the offensive in 1915 by Austria-Hungary against Belgrade, Austria-Hungary forces used the island to launch their attacks. After the World War I, island became part of the new Yugoslav state. After 1918, a small colony of 20 destitute inhabitants of Zemun built stilt houses on the island which was then colloquially called "Sirotinjska Ada" (Poor man's Island). In this period the entire area of the island was cultivated, mostly corn and watermelons. On the lower tip of the island, a beach was arranged and named Dorćol Beach or Lapat Beach. Also, a sandbank facing Zemun was adapted into the beach, being predecessor of the modern Lido beach, which was named this way at least before 1931.