Ceric hydrogen phosphate gels possess a very unique spatial organization, being nearlyamorphous materials with afibrous structure. Using a sol−gel approach, we succeeded in preparing bulkygels containing as much as 20,000 molecules of water per cerium atom. Supercritical treatment of thesegels made it possible to obtain thefirst ultralight monolithic noncarbonaceous aerogels with a density aslow as 1 mg/cm^3.