sociologist octavio rodriguez is a member of the organisation. sofia lopez and many others worked hard to make the ravine look the way it does now. 53 cubic metres of rubbish had to be removed. 8,500 trees were planted, donated by the botanical garden. but it all would have pointless if the people who live here had been neglected. take these maintain -- men, for example. many of them are former criminals. edwin tapasco parra served six years in prison for drug trafficking. now he and others from the neighbourhood are employed to maintain the ravine. they keep the brooks clean, cut the grass and take care of the trees. on other days they learn about plants and the environment. and they earn a little money doing so. ultimately they all have obligations. edwin has seven children to court -- support. >> some people decide to beg on buses or trains. others make it even easier for themselves, pick up a weapon and rob people. this programme helps us a lot and keeps us from doing that. most of us used to be troublemakers ourselves. >> tourists and visito