This site is not open to the public and is enclosed behind a high brick wall. However, it's only a few minutes walk from the Hal Saflieni Hypogeum and the Tarxien temples, so it seemed rude not to try to visit.
From the main square where the buses stop, head north north east along a road that bends to the right, until you reach a roundabout. Follow the footpath round to the first exit and cross the road immediately opposite church with a huge purple cross to its left.
There are signs to the temple but ignore these and go up the steps towards the church and in front of it, turn to your left. There's a gate in the wall facing you, and the wall that runs from here down the the building adjoining the church hides the temple.
The site is under the care of Wirt Artna and is open by appointment. I didn't have one, so had to content myself with standing on tip toes to balance my camera on the wall, and then walked round the block to find the back gate (which is beyond another gate, which fortunately was opened for me - sadly that gate keeper didn't have the set of keys to let me into the temple itself).
Excavations were carried out here in 1909 (Ashby and Peet) and a further survey in 1971 (Evans). There is a curved facade which is paved, and from the front of the structure, the upright megaliths left of centre lead through to the corridor of the trefoil building to the apses of the temple. Noteable features are to the left - niches in the wall, and the stone quern (sometimes described as a dugout canoe) across the threshold to one of the rooms. To the north, and visible on my photo taken from the back gate, is another structure, not at all well preserved, but thought to be another trefoil temple.