Cement Houses?

Helaman3:7 ,9 [Book of Mormon]

“And there being but little timber upon the face of the land, nevertheless the people who went forth became exceedingly “expert in working of cement; therefore they did build houses of cement, in which they did dwell…. And the people who were in the land northward did dwell in tents and in houses of cement, and they did suffer whatsoever tree of the land that it would grow up, that in time they might have timber to build their houses, yea, their cities, and their temples, and their synagogues and their sanctuaries, and all manner of their buildings.”
Cement, not mud, not adobe, but cement, the guy was building houses out of cement. I’m still hung up on this multiple temples thing for men who migrated from Israel so as to be faithful believing Jews. Who migrated before synagogue worship came to be widely developed in Jewish culture. Again Synagogue is a Greek word. And though Israelites had houses of prayer and so on before the development of what is known as the Synagogue today during the Babylonian Captivity which Nephi and Lehi fled. There are numerous problems with that aspect. But I want to know where the foundations of all these cement houses are? I want to know where this barren landscape is that is littered with cement houses.