Santiago

Santiago throws you straight into Chilean Spanish, the toughest version of the language to crack and the one that unlocks every other dialect once you do. Cabs, market stalls, and corner kiosks all speak fast, drop their s's, and pepper every sentence with weón and cachái. Six months here and you'll never struggle with another accent.

The city itself is a long corridor between the Andes and the coastal range, with the cordillera looming so close you can plan your day around whether the snow is visible. Bellavista on a Friday night, Lastarria on a Sunday afternoon, and a Maipo Valley winery two hours away by metro and bus. Practice scales here from the local panadería all the way to the high-Andean ski lift queue.

Costs are middle-of-the-pack for Latin America, but the trade-off is the best infrastructure on the continent. Gigabit fibre, the cleanest metro south of Stockholm, and the consistency of a country that runs on time. For a learner who wants Spanish at full speed without sacrificing daily-life functionality, Santiago is the underrated pick.