Portuguese settlers founded Ribeira Grande, now Cidade Velha, on Santiago in 1462. It became the first enduring European colonial town in the tropics and a strategic port in Atlantic expansion. Ships moving between Europe, West Africa, the Atlantic islands, and the Americas used its harbor. Streets, warehouses, churches, houses, administrative buildings, water sources, and later fortifications grew along the valley, making the settlement an early laboratory of Portuguese colonial urbanism.

Cidade Velha became deeply involved in the trafficking and sale of enslaved Africans. The pillory in the square is a powerful material symbol of punishment and authority, but enslavement shaped the entire town rather than one monument. Captives, interpreters, merchants, sailors, priests, craftspeople, farmers, servants, and free African and mixed communities created a complex society. Some enslaved people were forced onward across the Atlantic, while others labored and formed families on Santiago.

The town also served as an ecclesiastical center, with churches, religious houses, and a cathedral reflecting missionary ambition and local community life. Wealth and strategic importance attracted attack, including raids by Francis Drake and Jacques Cassard. The Real de São Filipe was built above the settlement to strengthen defense, yet repeated violence and changing shipping patterns contributed to decline. Administrative importance shifted to Praia, helping preserve ruins and the historic street pattern but reducing investment.

National conservation and UNESCO inscription have supported restoration of the fort, churches, streets, houses, and archaeological sites. Cidade Velha remains an inhabited town, so heritage policy intersects with housing, fishing, worship, schools, infrastructure, and local livelihoods. Reconstruction must identify new work and avoid creating a sanitized colonial setting. Archaeology should investigate domestic areas, landing places, burial grounds, and work sites, not only monumental Portuguese buildings.

Cidade Velha is significant for Atlantic exploration, Portuguese colonialism, Christianity, the slave trade, African diaspora, maritime conflict, and Cabo Verdean identity. Interpretation should center enslaved and free Africans and their descendants rather than treating the town merely as a European foothold. Conservation must manage coastal erosion, intense rain, drought, salt, wind, masonry, archaeology, development, and tourism. Community authority over commemoration and descendant research can ensure that preservation supports living residents while confronting the violence embedded in the Atlantic network. Conservation training in lime, stone, timber, and archaeology can create durable local employment. Interpretation across the town should connect the pillory, churches, fort, port, houses, and valley so that the slave trade is understood as a system embedded in every part of the colonial settlement.