Here is an easy way to find a special theme, just click on the theme.

Air Flight,  Aquatic invertibrates,  Birds,  Bridges,  Butterflies,  Cats,  Christmas,  Costume & Ethnic,  Crests & Flags,  Dogs   Fine Art,  Fish,  Flowers,  Football,  Fruit & Vegetables   Horses,  Insects,  Mammals,  Maps,  Medicine,  Military,  Music,  Olympics,  Plants,  Religion,  Reptiles & Amphibians,  Road Vehicles,  Scouting and Youth, Sea and River , Sport 

And if you want to find a country, just click on the country.