Salt hotel entrance. The Salt Palace and Spa, on the Uyuni Salt Flats in Bolivia. It is made entirely from salt bricks that were cut from the salt flats. There are twelve rooms, surrounding a court-yard, with flushing toilets but no showers. Although night-time temperatures can drop below 0 degrees Celsius, due to the flats high altitude, the bricks radiate heat that they have stored during the scorching hot day.