Clay is very old building material. It is amazing how it is not used as much nowadays. It is cheap, can be found in many places and used implementing many techniques. Clay is healthy, because dry clay doesn't absorb humidity and it protects the wooden frame from rot. Clay buildings are very long-lasting: i.e. there is a clay stable that was build in 1801 in Kaarina, Finland. The stable is still in use.

Architect, writer and humanist Nader Khalili researched and build plenty of clay houses during his long carrier. The clay houses are specifically for the poor areas, where people don't have money to build houses, but there is clay available on location. They indeed made some beautiful ones, but in the end it turned out to be too costly, because the fuel for firing the clay was too expensive. Khalili then worked for NASA in research for building houses in the moon and turned this study also to designing emergency shelters. I don't know why they fired the clay in the first place. To my understanding it is possible to use clay without doing so and just let it dry on its' own (slipform method).

The best clay source in Mega is probably the dried little lake just few ten meters away. The houses can be erased and taken down relatively quickly which is a good way to go with Mega.

Mega clay house  

Clay house on the move