The Mayan building is thought to be more than 1,000 years old. The vast complex is part of an ancient city approximately 100 miles west of the area popular with tourists Cancún, in Mexico.
The Kulubá palace is 180ft (55m) long, 50ft (15m) wide and 20ft six metres high.
Their mysterious civilisation flourished across central America including what is now southern Mexico, Guatemala, Belize and Honduras.
Mayan cities featured pyramid temples and huge stone buildings.
In addition to agriculture and metalwork, the Mayans developed sophisticated irrigation systems and invented a hieroglyphic writing system.
However, Mayan society suffered a mysterious and sudden collapse between AD800 and AD1000.
Scientists cite war, climate, disease and politics as possible causes, although cities including Chichén Itzá – which the archaeological dig suggests controlled Kulubá – flourished longer.
The conservation team are considering adding forest cover cleared during earlier excavation work to protect some of the more delicate buildings from adverse weather.
Natalia Tangarife, part of the conservation team, said: “One option which the site offers is using vegetation for conservation.
“This would mean reforesting specific sites so that trees can provide protection from direct sunlight, wind and other elements, for those structures which still have some of the original paint colours.”