United Nations
Unesco: World Heritage List
UNESCO designates natural and man-made sites of "outstanding universal value" as world heritage sites to protect them for future generations. View sites by country or use an interactive world map to locate sites from around the world...
Schools of California Online Resources for Education
Score: Castle Builder
A lesson plan with plenty of discussion and research questions, as well as links to examples and more information. You'll also find extension ideas and adaptations for students with special needs.
Other
China Daily: China Culture: Ancient Chinese Architecture: Concrete Music
An overview of ancient Chinese architecture, culture, and art.
Tech4Learning
Pics4 Learning: Images for Education: Castles
A treasury of photos of various castles from around the world! Although the images do not contain much information, they can be used as a visual reference for students of all grade levels.