Experts say they've discovered how to rescue Nero's underground Golden Palace from further decay and eventually reopen the ancient emperor's entertainment complex to the public: uproot trees in the park that sits atop it.

Archaeologists and restoration experts said Wednesday that research, including digital simulationsm, aimed at solving the Domus Aurea's chronic humidity problem, show that removing the trees will help prevent further damage. The nearly 2,000-year-old structure, under the Oppian Hill, was closed to visitors in 2010 after decades of stability problems. Tree roots and rainwater sink into the walls, damaging frescoes and causing parts of the ceiling to fall off.

Also being developed is a system to expel humid air.

Budget-tight Italy hopes private sponsors will pay for the 31-million-euro ($42 million) project.