john spiro of redwood city is a stone mason by trade. but for months now he's been donating his time and money to restoring this sculpture built in 1937. spiro says the project was vandalized but it's unclear when. >> they just picked at it little by little. and you know, it's almost like a jigsaw puzzle when you take a puzzle apart, it just comes apart in pieces. >> reporter: spiro expects to finish the restoration in about a year. he says he can protect it from the weather but he can't protect it from vandals. officials say vandalism has been a persistent problem in golden gate park. vandals often cover art with graffiti. the cost to clean up after vandal, hundreds of thousands of dollars. >> people would like to see more hours in their swimming pools and rec centers. if we're spending money trying to combat vandalism, that's less money we have for key services. >> reporter: the horseshoe has been renovated thanks to a charrable organization called the guards men. officials say perhaps one way to reduce vandalism is by closing the park