Ramunap Ruins

• WWizards of the Coast2017-04-18
  Official Ruling
  Desert is a land subtype with no special meaning. It doesn't grant the land an intrinsic mana ability. Other cards may care about which lands are Deserts.
• WWizards of the Coast2017-07-14
  Official Ruling
  If a Desert has an ability with a cost of "Sacrifice a Desert," you can sacrifice that Desert to pay the cost for its own ability.

Rulings via Scryfall

• WO
  Wizards of the Coast2018-05-10

  Ramunap Ruins was unbanned in brawl on May 10, 2018. Because of its singleton nature, we believe these cards will be less problematic in the Brawl environment. Part of what made these cards so powerful in Standard was the ability to play multiple copies and build highly efficient, consistent decks around them. Source: https://magic.wizards.com/en/news/news/future-brawl-2018-05-10
• WO
  Wizards of the Coast2018-01-15

  Ramunap Ruins was banned in standard on January 15, 2018. Ramunap Ruins adds a lot of "invisible power" to the deck, often acting as a virtual reduction to the opponent's starting life total. It also provides a high level of inevitability in matchups that go long, such as against the blue-black control decks popular at last year's World Championship. Without Ramunap Ruins, the general play pattern of the deck remains largely the same, but the deck will lose some amount of the free win percentage that this land contributed. Source: https://magic.wizards.com/en/news/news/january-15-2018-banned-and-restricted-announcement-2018-01-15