Architecture and cultural institutions established during this period expressed their own traditions. An opera house and Jewish cemetery were among the institutions established. Later in the 20th century, the city and region diversified its economy. The region exported timber, fish and their products, oil, minerals, and agricultural crops. It also derives considerable revenue from tourism and related crafts, as well as bakery, and carbonated drinks and beer. By 1999, the city had consolidated its four municipalities. The architecture and historical treasures reflect the colonial and early 20th-century European period, attracting an increased tourist trade in the 21st century. In addition it is a center of ecological tourism. It has become a major cosmopolitan city with strong roots in the Amazon, featuring a complex history and cuisine, Amazonian landscapes, nightlife, and a growing cultural movement. In 2012, 250,000 visitors were recorded. Many have been attracted since the Amazon rainforest was ranked as one of the Seven Natural Wonders of the World. Iquitos inaugurated international flights to the main hub of Panama City in 2012, with shared destinations with Miami and Cancún. Its international airport is expected to become one of six international air centers of Peru. The city was ranked as sixth on the list of "10 leading cities in 2011" of the "Lonely Planet" guidebook. The Historic Center of Iquitos has several structures that have been designated as part of the Cultural Heritage of the Nation: the Cathedral of Iquitos, the Iron House, the Old Hotel Palace, Cohen House, and more than 70 other buildings. Other landmarks are the Plaza de Armas; Jiron Prospero, an avenue that is the site of several shopping and historical areas; and the lively neighborhood of Belén, often dubbed the "Amazon Venice" for its many waterways. The city is also home to the Amazon Library, one of the two most important in Latin America. The city can be reached only by airplane or boat, with the exception of a road to Nauta, a small town roughly south (which is not connected to the country's main road network). Ocean vessels of 3,000 to 9,000 tons and draft can reach Iquitos via the Amazon River from the Atlantic Ocean, away. Most people travel within the city via bus, motorcycle, or the ubiquitous auto rickshaw ("mototaxi", "motocarro" or "motocar"). This is a modified motorcycle with a cabin behind supported by two wheels, seating up to three persons.