The concept of town-twinning began after World War II with the purpose of developing friendships and creating understanding between differing cultures, particularly between former enemies who were now working towards "peace and reconciliation" ("Twin towns and sister cities"). Twin towns, also called sister cities, is specifically a type of legal agreement between "towns, cities, countries," etc. aimed to "promote cultural and commercial ties" ("Twin towns and sister cities"). More specifically the idea of sister cities started with President General Dwight D. Eisenhower when he held a White House conference on citizen diplomacy in 1956. His goal was to "create bonds between different people from different cities around the world" in order to establish and maintain world peace ("Mission and History"). Sister cities are essentially formed when one city's government approaches another city with common interests and goals for their cities and can be formed when cities share culture, ethnic groups, and even industry in common. For example, the city of Cochabamba, Bolivia, is sister cities with both Cordoba, Argentina, and Miami, Florida. One reason is because Cochabamba was inhabited by the Spanish, making the city's dominant language Spanish, while Cordoba, Argentina, also became a colony of Spain's, making Spaniards one of the city's dominant ethnic groups, and Miami, Florida, was at one point claimed by the Spanish explorer Pedro Menendez de Aviles and is also a place for Cuban refuges, making Spanish speakers also Miami's majority. Hence we see that the two South American cities, Cochabamba and Cordoba, have bonded not only with each other but with Miami due to their shared Spanish language and culture.
Another example of South American sister cities is Manaus in Amazonas, which has many sister cities, including Rio de Janeiro in Brazil and even Salt Lake City, Utah. Manaus is located in the middle of the Amazon rainforest and surrounded by three different rivers, the Solimoes, the Negro, and the Amazon river, making it very isolated and remote. In fact, access to Manaus can only be achieved via boat and plane. The isolation of Manaus can be liked to Salt Lake City, which was permanently settled by the Latter-day Saints of the Church of Jesus Christ of Latter-day Saints, who were seeking isolation for religious practices. Salt Lake City is surrounded by the Wasatch and Oquirrh mountain ranges, canyons, and the Great Salt Lake, which is also surrounded by marshlands and mudflats. While the dominant religion in Manaus has become Catholicism, other missionaries have brought all kinds of faiths to the region, including Latter-day Saints missionaries. In fact, the Latter-day Saints church built its first temple in the city as recently as 2012. While Rio de Janeiro was settled by the Portuguese, it has become a diverse city, and while about half of the population is Catholic, similarly to Manaus, there is also a large percentage of Protestants. The Church of Latter-day Saints has also increased enough in numbers in Rio to announce plans for a Mormon temple in Rio de Janeiro, though "no groundbreaking date has been anounced" ("Rio de Janeiro Brazil Temple"). Hence, isolation, Catholicism, and Mormonism are all three things that join the two South American cities, Manaus and Rio, together, along with Salt Lake City.