Ribeira district: a historic and lively area along the Douro River. Clérigos Tower: landmark bell tower offering panoramic city views. Livraria Lello: one of the world’s most beautiful bookstores. Porto’s wine cellars: famous for Port wine and tastings, technically in Vila Nova de Gaia, a neighboring city just across the Dom Luís I Bridge, easily accessible from Porto's tourist areas. Palácio da Bolsa: the Stock Exchange Palace, a testament to Porto’s mercantile past.