LLake Cachi (Spanish: Lago de Cachí) is an artificial lake in central Costa Rica created by the Cachí Dam (Represa de Cachí), an arch dam which is located north of Tapantí National Park, to the east-southeast of Cartago in Cartago Province. The main town is Cachí, located on the east bank of the lake. Built in the 1970s, it was one of the first hydroelectric projects in Costa Rica. It has an installed capacity of 102 MW with three units of 34 MW capacity each

For several years now, Costa Rica has run on entirely renewable energy for an average of about 300 days per year. That means the government did not burn any oil, coal, or natural gas to power the country. No other country this size has done this.