Structures
get information about a building
compare several buildings
do computations with building properties
get information about a castle
compare several castles
find castles with specified characteristics
get information about a bridge
compare several bridges
do computations with bridge properties
get information about a tunnel
compare several tunnels
do computations with tunnel properties
get information about a dam
compare several dams
do computations with dam properties
Canals
get information about a canal
compare properties of canals
get information about a US mine
find US mines with specified properties