JUAN (St) DE LA FRONTERA, a town of South-America, in Chili, in the province of Chiquito, near the lake Guanacho. The territory of this town is inhabited by 20,000 native Americans, who are tributary to Spain. It contains mines of gold, and produces a kind of almonds that are very delicate. It is seated at the foot of the Andes, in W. Long. 66. 35. S. Lat. 23. 25.