Between the coastal mountains and the ocean, many areas of central Chile contain stretches of land that are lower than the Central Valley and are generally quite flat. The longest beaches can be found in such sections. The following regions are traditionally considered as being part of Chile's central Valley:  Historically, the Central valley has been the heartland of the country with the highest concentration of population (two thirds of the country's population) and, in addition, the area where the greater proportion of the economic productivity of the country is concentrated. Its economy is characterized by its diversity and the strongest pillars lie in the use of natural resources, through the copper mining, logging, agriculture and wine producing, fishing, and manufacturing sector. The main cities are: Santiago, Valparaíso, Viña del Mar, Quilpué, Villa Alemana, Quillota, Puente Alto, San Antonio, Melipilla, Rancagua, Curicó, Talca, Linares, Chillán, Concepción, Talcahuano, Coronel and Los Ángeles. William Barber  William Barber, Bill Barber or Billy Barber may refer to:         Zona Central  Zona Central can refer to:      The House of Atreus Act I  The House of Atreus Act I, released in 1999, is the ninth studio album by the American heavy metal band Virgin Steele. It has the subtitle "A Barbaric-Romantic Opera". This album is the first part of a metal opera inspired by the Oresteia, a trilogy of Greek tragedies written by Aeschylus which concerns the end of the curse on the House of Atreus. The music was intended to be the soundtrack for theatrical shows, with actors impersonating the characters of the tragedy. The metal opera was actually performed under the name "Klytaimnestra - The House Of Atreus" in European theatres from 1999 to 2001, with the production of the Memmingen Opera House company and Landestheater Production. The song "The Fire God" first appears on the 1986 Piledriver LP "Stay Ugly". All songs by David DeFeis except tracks 5, 7, 8, 15 and 18 by DeFeis / Ed Pursino        Santa Cruz de Lorica  Santa Cruz de Lorica is a town and municipality located in the Córdoba Department, northern Colombia.