Brazil.
My visits to Brazil were in the 1970's. It is a large country and there was an amazing variety of steam still operating, from modern 2-6-6-2's to ancient teakettles on sugar plantations. But many of the operations were small and the distances were great, so what I saw was but a small sampling.
My highest priority was the meter gauge Dona Teresa Cristina division of the National Railways or RFSSA. It was an isolated but busy coal hauling railway in Santa Catarina province in southern Brazil with the 2-6-6-2 articulateds built built by Baldwin in 1950 as well as a variety of other engines including modern 2-10-4's built by both Baldwin and Alco. The coal was hauled to a port at Capivari where it was loaded onto coastal steamers. The 2-6-6-2's were made surplus when a flood destroyed the steeply graded Lauro Mueller branch. Interestingly as the 2-10-4's wore out, the Teresa Cristina replaced them with used 2-10-2's from Argentina's General Belgrano railway. Presumably they were converted from oil to coal in the process. I never saw the 2-10-2's in Brazil, but there are several pictures of them in the Argentina section of this site.
I also visited the very interesting and colorful VFCO, a 76 cm line centered at Sao Joao del Rei north of Rio. I wish I had been able to spend more time on the VFCo, it was a colorful little railway in an exceedly pleasant setting.
The Teresa Christa survives as of this writing with diesels hauling coal to a large power plant at Tubarao. A part of the VFCo survives at San Joao del Rei as a wonderful museum and tourist railway.