Abstract: A dual dome structure comprising a first hemispherical dome of smaller diameter and a second hemispherical dome of larger diameter, the second hemispherical dome being of a material such as glass which will pass the rays of the sun to thereby create a highly heated space between the two domes. In accordance with one embodiment copper tubing is wound helically on the inner dome and salt water supplied thereto whereby the salt water will be evaporated and can be condensed to form fresh water. In a second embodiment the use of the dual dome structure to form a habitable space inside the inner dome is disclosed.