Urbanization has emerged as one of the most transformative processes of the twenty-first century, reshaping economies, societies, and ecosystems across the globe. While cities are often portrayed as engines of economic growth, innovation, and cultural exchange, rapid and unplanned urbanization poses serious challenges to sustainable development. The concentration of population, industries, and infrastructure within limited geographic spaces intensifies pressures on natural resources, social systems, and governance structures. These challenges are multidimensional, encompassing environmental degradation, social inequality, economic vulnerabilities, infrastructural deficits, and institutional limitations, all of which complicate efforts to achieve sustainability at local, national, and global levels. One of the most critical challenges of urbanization is environmental stress. Rapid urban growth increases demand for land, water, energy, and raw materials, often exceeding the carrying capacity of local ecosystems. Expansion of cities frequently leads to deforestation, loss of wetlands, and encroachment on agricultural land, undermining biodiversity and ecosystem services. Urban areas are major contributors to greenhouse gas emissions due to concentrated energy consumption, transportation networks, industrial activities, and waste generation. Air pollution from vehicles and industries, water pollution from untreated sewage and industrial effluents, and soil contamination from solid waste disposal directly threaten environmental sustainability and public health. The urban heat island effect, caused by dense construction and reduced green cover, exacerbates climate risks, increasing energy demand for cooling and intensifying heat-related illnesses. Water scarcity and mismanagement represent another significant challenge. Urbanization increases water demand for domestic, industrial, and commercial uses, often straining existing water sources. Many cities rely heavily on groundwater extraction, leading to declining water tables, land subsidence, and deterioration of water quality. Inadequate wastewater treatment infrastructure results in the discharge of untreated or partially treated sewage into rivers, lakes, and coastal zones, contaminating freshwater resources and marine ecosystems. Climate change further compounds these challenges by altering rainfall patterns and increasing the frequency of floods and droughts, making urban water management a central concern for sustainable development. Urbanization also generates enormous volumes of solid waste, posing serious challenges to environmental and social sustainability. Rapid population growth and changing consumption patterns increase the quantity and complexity of waste, including plastics, electronic waste, and hazardous materials. Many cities, particularly in developing countries, lack adequate waste collection, segregation, recycling, and disposal systems. Open dumping and burning of waste contribute to air and