Antofagasta is the largest city of the Norte Grande region and a product of the mining boom that hit the region in the 19th century. Profitable nitrate mines of the last century brought many foreign settlers to the city, and Antofagasta today possesses a markedly European feel in its architecture and ambiance. The Barrio Historico is home to many historic Victorian buildings, and the clock tower of the Plaza Colón is an exact replica of Big Ben. With 20 km (12 miles) of beachfront and a mild, dry climate, Antofagasta has also developed as a year-round beach resort. The highlight of its shoreline is the Portada, an enormous rock located just to the north of town which the sea has steadily eroded into a dramatic natural arch.