Krásno (literally meaning "Lovely Field") is first mentioned in the writings of Bartholomaeus Anglicus (also known as Bartholomew the Englishman) written in 1241, where the author praises the quality of Bohemian placers in Krásno and Krupka, which allegedly had been uncovered by English prospectors. Nonetheless, its existence then is not supported in historical annals (it is merely based on the fact that the largest deposits in the world had been located in Cornwall until exploitation began at Huber) and the foundation of the Krásno is thus dated after the year 1341 in connection with the family of Boreš of Rýzmburk and tin mining. Old Czech records denote the town as Ssenffeld, more recent ones, as Krásno nad Lesy, and the latest ones as Krásno nad Teplou. Latin and German documents denote it as Sonefeld, Schonfelt, Schonfeld, Schönenfeld, Ssynfeld, Schonnffeltt, or Schönfeld.
In 1355, Krásno was raised to the status of a township and it was granted mining freedoms and rights pertaining to tin mines and placers. In the times of the Pluhs (or Pflugs) of Rabštejn, Krásno was raised to a subservient mining town 1529. As in the town of Horní Slavkov, the tin mines in Krásno belonged among the leading mines in Europe. In 1547, the tin mines in the possession of the Pluh family were confiscated due to revolting against the overlord. By an edict of September 1, 1547, King Ferdinand I elevated Krásno to a royal mining town and awarded the town its coat-of-arms. In the late 16th century, the town was experiencing its first drop in tin output and even though several periods of growth followed, the 19th century saw the decline of the craft of pewterers and the rise of porcelain production.
In 1848, a devastating fire destroyed most of the town and its historical monuments, including the Church of St. Catherine. With the displacement of its German inhabitants after 1945, the subsequent rise of the Communist Regime, and the temporary closing of Slavkovský les (Slavkov Forest) for the purpose of establishing a military zone, the devastation of the town was inevitable. Its population dropped to a quarter and the number of houses to a third of its pre-war number. Apart from tin and wolfram ore, also uranium ore and feldspar was mined in the area in the 20th century.
The town can be proud of its mining museum, which is a part of the Karlovy Vary Regional Museum. The Mining Museum in Krásno is located on the site of the historical Vilém tin mine founded on the Gellnauer vein system. The mine had been in operation with short interruptions until the 1990’s. The Vilém Mine complex comprises of a milling plant, workshops, a hoist tower with a hoist house, machine room, a gatehouse, as well as the building of one of the oldest transformer stations on our territory. The main museum building, reconstructed between the years 1994 and 1998, served as a tin ore preparation plant in the 18th and 19th century.