A dachais a seasonal or year-round second home, often located in the exurbs of post-Soviet cities. A cottage or shack serving as a family's main or only home, or an outbuilding, is not considered a dacha, although recently purpose-built dachas have been converted to year-round residences, and vice versa. In some cases, dachas are occupied for part of the year by their owners and rented out to urban residents as summer retreats. Dachas originated as small country estates gifted by the tsar, and have been popular among the upper and middle classes ever since. During the Soviet era, many dachas were state-owned, and were given to the elite of the Communist Party of the Soviet Union (CPSU). They were extremely popular in the Soviet Union, because people did not have an opportunity to buy land and build a house where they wanted, and also because they lacked other opportunities to spend their time and money.