Entire neighbourhoods of central Madrid are dug up at the moment, giving the city a 19th-century feel. Cars cannot slither down those sandy, soily lanes, and you expect a horse and cart to trot into view.
Notices say "renovation" is afoot, but I remember some of these areas being renovated last year, when muddy paths were eventually paved with attractive cobblestones. However, after some muttering that the work was shoddy, the digging began again.
But now, Madrid has dug a hole with a purpose. The authorities are looking for Diego de Velazquez, whose bones are thought to lie under the Plaza Ramales, near the royal palace. The spot was earmarked for "renovation" last year. Then someone alerted the town hall that Spain's greatest painter, who was born 400 years ago and died in 1660, lay buried in the vaults of a church that once stood on the site.
It is the most talked-about hole in town. After digging began in the spring, the hole was screened by corrugated metal fences, but public interest is such that a panel on each side was replaced by a wire mesh, giving a good view of the subterranean brickwork of the 17th-century church of San Juan. The building was demolished in 1810, but the vaults were undisturbed.
After initial excitement when the church's foundations were uncovered, it became clear that a quick result was unlikely. Historians do not know where in the church Velazquez was buried: so far they have turned up four cadavers and the bones of another 50. Many more remain.
How to identify the master? At this point speculation shades into the fantastic. A forensic science expert proposes to plump out the fingers with injected glycerine to compare the prints with any found on Velazquez's canvases; to examine a bone for traces of lead consistent with the artist's materials, and to reconstruct his face by digital computer imaging and compare it with existing portraits. Others propose to match the DNA with some of Velazquez's extraordinarily diffuse descendants.
Complaints began that all this smacked of necrophilia, and should be stopped. Some newspaper commentators condemn attempts to resurrect Velazquez's physical remains as a kind of idolatry. What matters, they say, is his work. Let his bones lie.
This line of thought prospers as more emerges about the artist's less- than-saintly personality. It turns out he was something of a toady, pestering royal patrons for a title, which he was finally granted shortly before his death.
But one cultural commentator at the weekend dismissed arguments that digging for Velazquez was morbid and futile. He says the work must go on because "we are looking for the best of what we have been, the best that we can be". So there we have it. Madrilenos dig holes because they are looking for themselves.
But with September here, and traffic gridlocked once more, they will want all the holes covered up as quickly as possible so they can take the swiftest route from A to B.