Kolkata has many buildings adorned with Indo-Islamic and Indo-Saracenic architectural motifs. Several well-maintained major buildings from the colonial period have been declared "heritage structures";[231] others are in various stages of decay.[232][233] Established in 1814 as the nation's oldest museum, the Indian Museum houses large collections that showcase Indian natural history and Indian art.[234] Marble Palace is a classic example of a European mansion that was built in the city.