By Tim Franks, BBC Sports News Correspondent, Athens
The Softball stadium in Athens
In ancient Greece, Cassandra prophesised the fall of Troy, and was ignored. In modern Greece, another alarm has sounded: London, beware.
The warning comes from the staging of the Olympics in Athens in 2004. No-one knows for sure how much the Games cost Greece. The official figure is £9.6bn but Sotiris Triantafyllou, one of Greece's most experienced sports journalists, says that the "real" figure is a "mystery". All he can say for sure is that the official estimate is "not true... it's two or three times that amount".
Rarely, if ever, do Olympic Games make money for their hosts. But the Greeks' profligacy was perhaps without precedent.
Exhibit A is the great, wind-blown expanse of the Helliniko Complex, built on the site of an erstwhile Athens airport. It included separate, permanent venues for softball, baseball and hockey. Today, most of the sites lie unused; chained off, mould on the walls, weeds poking through the concrete.
The man charged with clearing up the mess is Yiorgos Panayiotou, chairman and CEO of the state-owned Olympic Properties Company.
He is politely, but forensically withering: "Our view, albeit in retrospect, is that some of these facilities ought not to have been permanent. Nobody plays softball in Greece. Hardly anyone plays hockey in Greece. You don't need a permanent baseball pitch in Greece."
Mr Panayiotou only took charge in the middle of last year. He is now trying to draw the poison from endless legal tangles over how the Olympic venues might be redeveloped by private companies, and from the cost in the mean time of maintaining sites which he says, after the Games, were "almost left to nature".
He says that future Olympic hosts should learn from Athens' hamfistedness. One lesson is to ensure that whatever you build has the sturdiest legal, planning and environmental framework, to allow you to dispose of it as you see fit. Another, he delivers with a roar of laughter: "If someone tells you, 'I can set up this structure for you - as a light and temporary structure - and instead of 50m (for a permanent venue), pay me 25m'... you should not send him away."
On that, the organisers of the London Games may be able to point, proudly, to the temporary, 12,000-seat basketball and handball arena, in the Olympic Park. This striking, fluffy marquee will be dismantled after the Games.
But nearby, lies a much bigger venue, whose future is shortly to be decided, and whose fate will be controversial and costly.
The Olympic Park Legacy Company has already, under pressure, postponed its recommendation on whether the main stadium should be given to the Premier League club, Tottenham Hotspur, who say they will rip out the athletics track, or to West Ham United, who say they will keep the track.
On this, too, Athens has something to say. The main Olympic stadium, was not purpose-built for the Games in 2004. But it was renovated at some expense. It now rents itself out to two of Greece's biggest football teams, Panathanaikos, and AEK. Both teams, however, are keen to move out, and build their own, new stadiums.
It's not a stadium for football. It's a stadium for Olympic Games. You don't feel the mood of the game
Grigoris Kanarelis, secretary of Panathanaikos fan club
The reason, according to Grigoris Kanarelis, general secretary of the main Panathanaikos fan club, is simple. Mr Kanarelis is speaking, tie loosened, cigarette lit, in the city centre offices of the fan club, the walls painted the pounding green of the team strip.
"The supporters aren't near the players," he explains. "It's not a stadium for football. It's a stadium for Olympic Games. You don't feel the mood of the game."
Empty stadiums are difficult to judge. But when I visited the Olympic stadium on a rain-lashed winter night, even from the front row, the football pitch did seem coldly distant, separated as it was by a nine-lane athletics track. Mr Kanarelis says the lesson for Spurs or West Ham is clear: "Get rid of the athletics track. Otherwise it's a crime. Nothing else."
The problem for the Olympic Stadium is that it relies heavily on the income generated by the two football clubs.
One former senior stadium official, speaking on condition of anonymity, told the BBC that the venue costs about 35m a year to run. Its income, which only amounts to about 9m or 10m a year, comes mainly from Panathanaikos and AEK - in rent and a 15% commission on ticket sales. A small proportion comes from the stadium's other events, such as concerts and conferences. The government currently covers the shortfall. But to lose the football tenants would hurt, deeply.
As with London, a great dumper-truck of money was poured into the Athens project, not just into the venues, but also the local transport. The city saw new roads, metro stations and tram lines built.
On the day I was there, I watched five trams swish past along the beach-side route which had been created for 2004. There was not a single passenger on board.
Petros Ferentions, the manager of the local branch of the Flocafé chain, said it had not been worth it. Yes, he said, business - which had collapsed for everyone in the past year - would definitely be worse if there were not a tram to help bring customers.
"But in general people don't use the tram as much as it was expected. I don't believe the state nor the citizens have profited," he said.
The good news for London is that it is unlikely to repeat all of the mistakes in Athens. The organisation has so far been better, the British economy appears not to be quite so hammered, and history, in any case, rarely offers perfect symmetry.
But such is the vastness of the expenditure demanded by the high priests of the International Olympic Committee, that the traps abound. And as Athens still bears witness, once you are ensnared, it can take a long time to emerge.