However, over 77% of the population is concentrated in five communities, with about 51% in the town of Tequisquiapan alone. The other major population centers are San Nicolás, La Fuente, Fuentezuelas and El Tejocote. The main economic activity of San Nicolás is the production of cinderblock, followed by agriculture. La Fuente's main economic activity is agriculture with chili peppers, corn, tomatoes and beans as principle crops. La Trinidad is the center of opal mining in the municipality, but it also cultivates corn and beans. The town and municipality are located in the far southeast of the state of Querétaro, just north of the small industrial city of San Juan del Río, and within one hour driving distance from the city of Querétaro and two hours from Mexico City. This is one reason why it is a popular place to visit on weekends and many second homes have been constructed here. The municipality borders the municipalities of Colón, Ezequiel Montes, San Juan del Río and Pedro Escobedo with the state of Hidalgo to the east. The municipal government consists of a municipal president and thirteen officials called “regidors” to represent the various communities of the municipality. The overwhelming majority of the population is Catholic, with a small but growing number in Evangelical groups and Jehovah's Witnesses. There is one special education school which serves 160 students with sixteen teachers. There are sixteen preschools serving over two thousand young children between four and six years of age. There are thirty-six primary schools. Middle school education is offered through two modes, distance education called “telesecundaria” and a general middle school system. Most attend the latter which are located in the larger population centers near the municipal seat. The telesecundarias are located in the communities of La Fuente, Los Cerritos, Fuentezuelas, El Tejocote, San José la Laja, Santillán, El Sauz, La Trinidad and San Nicolás. High school and vocational school education is offered on five sites. Almost all residences in the municipality are occupied by their owners, with an average of 4.9 occupants per household. Basic municipal services such as running water, garbage and other services are available to 90% or more of the population with the exception of street lighting, which is available to only 60%. Residential construction has changed significantly since the mid 20th century with the introduction of concrete and cinderblock, which is now used in almost all new construction. This