Mnajdra is made of
coralline limestone, which is much harder than the soft
globigerina limestone of Ħaġar Qim. The main structural systems used in the temples are
corbelling with smaller stones, and
post and lintel construction using large slabs of
limestone. The cloverleaf plan of Mnajdra appears more regular than that of Ħagar Qim, and seems reminiscent of the earlier complex at
Ġgantija. The prehistoric structure consists of three temples, conjoined, but not connected: the upper, middle, and lower. The upper temple is the oldest structure in the Mnajdra complex and dates to the Ġgantija phase (3600-3200 BC). It is a three-apse building, the central apse opening blocked by a low screen wall. The pillar-stones were decorated with pitmarks drilled in horizontal rows on the inner surface. The middle temple was built (or possibly rebuilt) in the late
Tarxien phase (3150 – 2500 BC), the main central doorway of which is formed by a hole cut into a large piece of limestone set upright, a type of construction typical of other megalithic doorways in Malta. This temple appears originally to have had a vaulted ceiling, but only the base of the ceiling now remain on top of the walls and, in fact, is the most recent structure. It is formed of slabs topped by horizontal courses. The lowest temple, built in the early Tarxien phase, is the most impressive and possibly the best example of Maltese megalithic architecture. It has a large forecourt containing stone benches, an entrance passage covered by horizontal slabs, one of which has survived, and the remains of a possibly domed roof. The temple is decorated with spiral carvings and indentations, and pierced by windows, some into smaller rooms and one onto an arrangement of stones. == Functions ==