What is this material?
Steel
What is this material ?
Iron
What is this structure?
Anthill
What is this material?
Bricks
What is this structure ?
House
What is this structure ?
Wood House
What is this structure ?
Igloo
What is this material?
Coral
What is this material?
Stone
What is this structure?
Dam
What is this structure?
Reef
What is this structure?
Beaver dam
What is this material?
Concrete / Cement
What is this material ?
Nail
What is this material ?
Wood
What is this structure ?
Bird Nest
What is this structure ?
Spider Web
What is this structure ?
Mansion
What is this structure ?
Castle
What is this structure ?
Golden Gate Bridge
What is this material?
Fiber
What is this structure ?
Building
What is this structure ?
Tipi
What is this structure ?
Mountain
What is this structure ?
Eiffel Tower
What is this material?
Soil / Ground