YEARS  AGO
The earliest known use of several architectural features can be found in the temples of Malta and Gozo including forecourts, retaining walls, corbelling, the horizontal arch.

Although ceilings have not survived, the temples were roofed when they were in use.  Stone carvings and decorations have deteriorated noticeably in the short time since they have been exposed to the elements.  They must have been protected originally to have survived.  Small models left by the builders do illustrate a roofing system.   The Hypogeum also suggests how the ceilings were finished.

Researchers are not agreed, however, about how the roofing was made.  Some think that stone was used to span the walls; others suggest brush and animal skins.  Another possibility might be a combination with timber and plaster.

In many of the temples the curved interior walls are corbelled.  The higher rows of stone overlap the course below to narrow the distance across the top.  This is an important building technique that appears for the first time in the temples.
 

Hagar Qim Temple, under its new protective cover