Every project needs information about where on the world it is located.
The brightness distribution of the sky is then determined as a function dependent of the sky position. No simulation can currently be run without this information, so it is a good idea to fill it in right at the start. This is the name of a place that can be used to communicate the location to people. It is not directly used in simulations, except in human readable comments in output files and as a search key when looking up locations in the internal database. This button offers to select a location from a database of many cities worldwide.