The birthplace of port wine, Porto, is historically known as a merchant town. Situated on the Douro River, the Cais da Ribeira is an extremely colorful area filled with bars and restaurants and is also amazing for people-watching. As the banks of the river are rather steep and unforgiving, the monumental Luís I Bridge was constructed in the 19th century. Besides being a site to behold, the city's light railway uses the top level, while pedestrians and vehicular traffic can cross on the lower level. The Clérigos Church features a 75-meter-high tower, and a climb to the top will reward visitors with beautiful views of the city. Some of the more luxurious areas of the city can be found in the Praça da Liberdade, while there are many beaches to choose from in the vicinity of the city, as the Duoro River enters the Atlantic Ocean. This area is known as the Foz do the Douro, and there is a lovely promenade modeled after the one in Nice, France.