All buildings have numbers to indicate the current level. If the building has an
up-arrow, it is ready to be upgraded, (all requirements have been met, and resources are available). This function can be disabled
in the options section.
The gold coin symbol above the Treasury means your deposit is ready to
be picked up, or a deposit can be made. If the icon is missing it means you have gold deposited that has not reached
maturity yet.
The book icon above the University means that you can do some research. If the icon
is missing, then all research queues are full.
The cross icon above the Hospital means there are patients requiring attention.
