**2. Livable City as an objective**

Livability is becoming an increasingly important factor in sustainability. Based on that, livable City works to improve cities' quality of life [11, 12]. That shows the importance of creating a city with pleasant city spaces, roads, and an entire environment that makes walking, biking, and transit the best choice for urban communities. Urban public area, well designed, and well maintained, and safe housing is more and more affordable [13]. There is a global trend toward livable cities because this is a practical approach to sustainable urban planning and design.

Sustainable city development aims to improve the quality of life [11] of citizens and reduce cities' impact on outside resources. The revitalization of GOS and urban structures forms the basis of sustainable urban planning in cities [14]. Urban ecosystems with excellent urban governance in preparing plans and diversity of local ecosystem services [10]. The rapid development of urban areas is a challenge and opportunity to design more livable, healthier, and more resilient cities. It can be adaptive to the effects of climate change [10]. Planner and Urban Designers play an essential role in determining livable cities' physical quality and characteristics [15]. Environmental conservation efforts with an adequate investment are necessary to realize ecological infrastructure, ecological restoration, rehabilitation of urban area ecosystems, and revitalization of urban open spaces, which are ecologically and socially desirable and often economically beneficial [10].

Improving the quantity and quality of GOS will increase biodiversity and the environmental variety of urban ecosystems [16]. Application of landscape ecological principles [17–19] to green structure planning [20–23] also corresponds to two patterns: nature in cities [14], and urban patterns in nature [24]. According to Frischenbruder and Pellegrino, [25], in their study in eight cities in Brazil, green networks could make meaningful contributions to more livable cities by uniting planning and ecology [14]. In 1996, the United Nation's Habitat Conference introduced live ability and noted that every City should be habitable [26]. Hahlweg [27] states that City as a family defines a city that can live as a city for all people or a city that can accommodate all the city community's activities and is safe for the entire population.

According to Timmer [28], a city that can live in refers to an urban system that makes physical, social, mental, and personal contributions to its inhabitants. There are five fundamental aspects of great, livable cities: robust and complete neighborhoods, accessibility and sustainable mobility, a diverse and resilient local economy, vibrant public spaces, and affordability (**Figure 1**). An essential aspect of realizing livable cities related to spatial planning is the realization of dynamic urban open space following quality standards and its facilities' needs. The existence of urban public areas following its function (social, ecological, and esthetic functions) makes it increasingly evident that increasing the quality of urban open space will contribute to the sustainability of urban development. In this chapter's discussion, the City's GOS Revitalization program is the focus of efforts to provide a better public space.

Improving the quality of urban GOS related to social, ecological, and esthetic functions contributes significantly to the realization of Urban Resilience [29–31]. Success in improving the quality of social space will contribute to the provision of community social space, space for social interaction, space for relaxation, and sports that are important for improving people's physical and spiritual health. Improved urban areas' ecological functions will contribute to biodiversity and animals, improve the quality of the microclimate of the city/region, air purification, groundwater conservation efforts, and increase rainwater absorption by reducing surface runoff rates [32]. It is significant for the improvement of urban ecosystems. The successful revitalization of urban space will also improve the visual quality of urban areas, which is essential for realizing a harmonious city environment between the natural environment and the landscape architecture as an artificial environment.
