Four days in Valletta: a city the knights built in case the Turks came back

Come in the way everyone has since the 1560s, through the gap in the bastion at the landward end. The current gate is the fifth, cut by Renzo Piano between 2011 and 2014, and it leaves the breach open to the sky rather than roofing it, so you walk in between two sheer walls of rock.

Straight ahead is the ruin of the Royal Opera House, bombed in 1942 and left as it stood for seventy years, now an open air theatre inside its own broken colonnade. Beyond it, the parliament sits on stilts in two rough stone blocks that people either love or complain about at length.

Then go up to the Upper Barrakka Gardens for the view that sells Malta: the whole Grand Harbour, the Three Cities on the far side, and the batteries below. The gun on the terrace under the gardens is fired at noon and at four, and four is the better one because the light is on the water.

Be at St John's when it opens. From outside it is a fortress with two towers and no ornament at all, which is what the knights wanted when it went up in the 1570s; inside, every surface is carved, gilded or painted, and the floor is a carpet of marble tomb slabs laid over the knights buried beneath them.

In the oratory hangs the Beheading of Saint John the Baptist, painted by Caravaggio for this room in 1608 while he was a knight himself. It is the largest canvas he ever produced and the only one he signed, in the blood running from the saint's throat. He was expelled from the Order and out of Malta within months.

The archaeology museum is five minutes up Republic Street in the knights' old Auberge de Provence, and it holds what was taken out of the temples: the Sleeping Lady from the Hypogeum, the heavy seated figures, the flint and obsidian. See it before the temples rather than after and the sites make far more sense.

Finish at the Grand Master's Palace, which has been the seat of whoever ran Malta for four and a half centuries and now houses the president's office. The armoury alone holds enough plate for a small army.

Under the gardens you stood in on the first afternoon is a complex of tunnels cut into the rock, from which the defence of Malta was directed through the worst of the bombing and, later, the landings in Sicily. The rooms are kept as they were, down to the plotting table and the chalk on the boards, and they are cold, which in July is a feature.

Then take the ferry across the Grand Harbour. Senglea is a single narrow peninsula packed tighter than anywhere else in Europe, all steps and washing lines, and at its tip is a stone lookout carved with a giant eye and ear, so that anyone approaching knew the sentry inside was watching. The view back at Valletta from there is better than the famous one looking the other way.

In the afternoon, walk the length of Republic Street to Fort St Elmo at the point. This is where the Great Siege was decided: the fort held out against the Ottoman guns for a month in 1565 and everyone in it died, which bought the rest of the island the time it needed. The National War Museum inside runs from the Bronze Age to the George Cross the whole island was awarded in 1942.

Malta's temples are older than Stonehenge and older than the pyramids at Giza, and the most elaborate of them sits in a suburban street ten minutes from the runway. Tarxien is four linked structures built and rebuilt between roughly 3600 and 2500 BC, with spiral carved slabs, animal reliefs and the lower half of a colossal skirted figure.

It is covered by a canopy now, and it takes about an hour with the audio guide. Having seen the originals of the carvings in the archaeology museum two days earlier makes the difference between a field of stones and something you can read.

The airport is a few minutes further on, so the only cost is getting up in time.