Ángel Mancera announced the construction of two more stations and a terminal for Line 12: Valentín Campa, Álvaro Obregón and Observatorio, both west of Mixcoac. With this, Line 12 is to be connected to Line 1, providing new metro access to the Observatorio zone, which will become the terminal for the intercity train between Mexico City and Toluca. Archaeological finds The metro system's construction has resulted in more than 20 thousand archeological finds, from various time periods in the history of the indigenous people. The excavations needed to make way for the rails gave opportunities to find artifacts from different periods of the region's inhabitants, in areas that are now densely urbanized. Objects and small structures were found, with origins spanning from prehistoric times to the 20th century. Some examples of artifacts preserved by the Mexican National Institute of Anthropology and History (Instituto Nacional de Antropología e Historia de México (INAH)) are: parts of pyramids (like an altar to the Mexica god Ehecatl), a sculpture of the goddess Coatlicue, and remains of a mammoth. The altar to Ehécatl is now in Pino Suárez station, between lines 1 and 2, and is called by the INAH the smallest archeological site in Mexico. The metro has led to a large quantity of archeological finds, and has also let archaeologists understand more about the pattern of ancient civilizations in the Mexican capital by analyzing its underground from various time periods. Architecture Distinguished architects were hired to design and construct the stations on the first metro line, such as Enrique del Moral, Félix Candela, Salvador Ortega and Luis Barragán. Examples of Candela's work can be seen in San Lázaro, Candelaria, and Merced stations on Line 1. Network map Lines, stations, names, colors, and logos Each line offers one service only, and to each line, a number (letter if feeding line) and color are assigned. Every assigned color is present on square-shaped station logos, system maps and street signs, and neither colors nor numbers have been changed. Line B is the only exception to the color assignment, as green (upper half) and grey (lower half) are used, producing thus bicolor logos and signs. Gray only may be used to avoid confusion with line 8, which uses a similar green. The names of metro stations are often historical in nature, highlighting people, places, and events in Mexican history. There are stations commemorating aspects of the Mexican