Punta Arenas is an interesting port city at the southern end of the Chilean peninsula. Given it's long history as a penal colony, sheep farming and shipping zone through the Strait of Magellan, it is the largest city this far south [over 100,000] and has a strong naval presence. All this has left the city with a considerable number of grand turn-of-the-century buildings especially in the center. The cemetery rivals those in Buenos Aires and is a nice walk from the center.
Today Punta Arenas is a major starting point for tours through the Strait and Antarctica. It also has the southern most major airport in Chile, hence one way to get to Puerto Natales and Torre del Paine national park. You wouldn't come here just for the town itself, but it's worth spending a night to see the town.