Part of a chain that ran from Lima to Buenos Aires during viceregal times, La Posta de Hornillos is a beautifully restored staging post 11km south of Tilcara. Founded in 1772, it was the scene of several important battles during the independence wars, and remained an important stop on the road to Bolivia until 1908, when the La Quiaca railway opened. The interesting exhibits here include some impressive and fierce 17th-century swords, 16th-century arrowheads and a fine 19th-century carriage.
It's set beside a working farm backed by mineral-streaked mountains.