The research was conducted to support Sustainable Development Goals number 11 and 15. It proposed a new ecotourism attraction in Kupang city, East Nusa Tenggara, Indonesia. Currently, the only scientific tourism site in Kupang is the Oelsonbai Forest. It is a tourist destination with specific visitor characteristics. Oelsonbai functioned as a place for research, ex-situ conservation, and the development of a scientific tourism model. In accordance with its designation, visitors to the Oelsonbai consist of two major groups, namely the research group and the education group. The grounded research results found that Oelsonbai Forest has not been fully explored, and the tourist attraction is concentrated in the Timor deer enclosure, the Rote snake-necked turtle captivation, and the sandalwood nursery. However, 41 bird species from 23 families were found in Oelsonbai and 23% are Timorese species. The diversity of birds in Oelsonbai is a potential object of ecotourism. Birdwatching is an option to add to Kupang’s beach-dominated tourist activities. Based on visitor characteristics, the area potency, and the Oelsonbai’s designated function, birdwatching can be developed as a new ecotourism product in Kupang. This step is a strategy to maintain Kupang as a sustainable city by managing the urban forest ecosystem.