The capital of the Santa Fe Province is linked to Paraná, capital of the Entre Ríos Province, via a tunnel beneath the River Paraná (see below). Mainly important as an agricultural and industrial center, Santa Fe’s colonial past is still visible in its streets and squares, though there are also many modern buildings. The nearby city of Rosario, on the west bank of the River Paraná, was where the Argentinian flag was first raised and its biggest attraction is the impressive, boat-shaped Monumento Nacional a la Bandera (Monument to the Flag). La Semana de la Bandera (Flag Week) is celebrated annually in June. Nearby is the town of Rufino, an important center for cattle raising. Walking and trekking are popular in the Lihue Calel National Park, an area consisting mostly of desert, located some 226km (142 miles) southwest of the city of Santa Rosa, and known for its pink granite rock formations (reaching up to 600m/1968ft).