São Raimundo Nonato, Brazil

With a population of just 44,208, São Raimundo Nonato is a sleepy outpost in the remote southern region of Brazil's Piauí state. The city's main claim to fame is hosting part of the Serra da Capivara National Park, a UNESCO World Heritage site known for its prehistoric cave paintings. However, the bureaucracy involved in accessing this natural wonder can be a persistent headache. Travelers should also be prepared for the region's isolated, rural character - the nearest major city, Teresina, is a 576 km drive away. Overall, São Raimundo Nonato is best suited for the most intrepid adventurers and archaeology enthusiasts willing to brave its logistical challenges.