A dolmen, also known as a portal tomb/grave, quoit, or cromlech is a type of single-chamber megalithic tomb, usually consisting of three or more upright stones supporting a large flat horizontal capstone (table). In Maltese, dolmens are called l-imsaqqfa (roofed).
Dolmens were usually covered with earth or smaller stones to form a barrow, though in many cases that covering has weathered away, leaving only the basic stone structure of the burial mound intact.
It remains unclear when, why, and by whom the earliest dolmens were made. The oldest known examples are to be found in Western Europe, where they were set in place around 7000 years ago. Most of those found in Malta date from the early Neolithic period (4000 to 3000 BC).
Many questions as to who built these structures and their original purpose remain unanswered. The most widely accepted theory is that all dolmen are tombs or burial chambers. There is however no firm evidence that even this theory is correct.
On the lower slopes of the hill some 200 metres inland down a minor road leading from the coastal road at Qalet Marku are the Ta' Hammud dolmens. The best preserved is dolmen A which consists of a capstone measuring 2.4 metres by 1.2 metres and 56 cms thick resting on small boulders only some 50 cms off the ground. The rock beneath the capstone has been hollowed out in the centre to form a recess large enough for cremation burials. In 1954 sherds were found in the hollow dating the monument to the early Bronze Age.