I live in Cartagena, Spain's 24th largest city, which was built on five hills and founded c. 227 BC by Hasdrubal on the site of the much older Tartessan city of Mastia. One of the hills isnow under threat from a developer. Every day a couple of huge excavators hammer away at the lower slopes of Monte Sacro, chipping away at history.

Protests are being led every Friday by Javier Garcia del Toro, a professor of archaeology at Murcia University. He recently bought a toy excavator from El Corte Inglés for the politician whogave building permission for four blocks of flats. He also cleverly dished out mackerel paté to some of the protesters, claiming it was the authentic aphrodisiac Roman garum.

Last week, about 300 people turned up. Garcia del Toro made himself heard against the sound of breaking rock with a loudspeaker. Some of us went and stood by the diggers with our placards, singing'No nos moveran' until the National Police arrived. No one was arrested and we all went home.

In the days of the Carthaginians, this hill was sacred to Baal-Hammon, afterwards, Kronos. Monte Sacro was once home to an altar of peace that is now in a museum in Barcelona. The beautiful arapacis dates back to the time of Augustus. The only thing that has been found recently is a 17th-century wall, which the developer, Portmán Golf, promised to preserve. But accidents can happen whenyou are breaking into solid rock: the whole area needs to be excavated slowly and thoroughly by hand. The nearby hill, the Molinete, once also under threat of development, has revealed manytreasures: a house with frescoes, an almost intact gym floor. One of the other hills contains one of Spain’s top tourist attractions, a Roman theatre. That was discovered only a few decades ago.But even if no more important remains exist, it is vital that Monte Sacro is saved. Otherwise Cartagena will become a four-hill city, as unthinkable as Rome only having six.

There is a Facebook group, Salvemos El MonteSacro de Cartagena, which co-ordinates events. Tomorrow there will be another demonstration. This time it is hoped there will be enough protesters to provide a human chain around the hill.But it's a big hill.