Morro do Castelo, situated in Rio de Janeiro, Brazil, was a prominent hill that marked the city’s foundation in the 16th century. Visitors once encountered colonial fortresses, Jesuit colleges, churches, and administrative buildings that defined the city’s early development. The site is notable for housing the first cathedral of Rio, the founding stone brought by Estácio de Sá, and the remains of the city’s founder. Although demolished in 1922 to make way for urban expansion and the International Exhibition of Independence, Morro do Castelo remains a symbol of Rio’s colonial past, remembered through historical records and cultural legends.