The center ( `` Downtown '' in American English or `` CBD '' - central business district - in other English use ) , is the place where the city was founded . It is the busiest area , most of the financial institutions of Curitiba are located there . The centro ( `` Downtown '' in American English or `` CBD '' â `` central business district â `` in other English use ) , place of foundation of the city , is the most bustling area , which concentrates most of the financial institutions of Curitiba .