Tolerance of sexual diversity in certain indigenous cultures is widespread, especially among Isthmus Zapotecs and Yucatán Mayas. As the influence of foreign and domestic cultures (especially from more cosmopolitan areas like Mexico City) grows throughout Mexico, attitudes are changing. This is most marked in the largest metropolitan areas, such as Guadalajara, Monterrey, and Tijuana, where education and access to foreigners and foreign news media are greatest. Change is slower in the hinterlands, however, and even in large cities discomfort with change often leads to backlashes. Since the early 1970s, influenced by the United States gay liberation movement and the 1968 Tlatelolco massacre, a substantial number of LGBT organizations have emerged. Visible and well-attended LGBT marches and pride parades have occurred in Mexico City since 1979 and in Guadalajara since 1996.