Location

Attribute of events or actions, not people or objects

While the CASTEMO ontology technically allows you to attach locations directly to people or objects, it is more proper to attach place to Events. For instance:

• a Person can have the Event of birth (labelled for instance "birth of Alexander the Great"), death, etc., which will be classified as Event of that class (e.g. "birth", "death", with SCL something like "life-cycle event"), and will have its place (and time and potentially other circumstances) attached;
• a manuscript (Object), or text (Territory) or textual version (Resource) can have the event of composition, which will again have its location (and time and other circumstances).

This is ontologically more appropriate, if you think what location really describes, but also practically, for instance if you need to treat more complicated spatial or temporal relations such as spatial uncertainty.

Such Event with a location will be attached to the entity through a property as usual, e.g.:

P Alexander the Great - PROP - C event of birth - E birth of Alexander the Great

Coordinates

Coordinates are generally quite a straightforward property - attach them a metaproperty to the location as a coordinate pair, with Concept such as "coordinates (lat; long)", and the value as Value entity:

It is a good idea to mark localisation precision, usually with values such as "precise" and "approximate", which are of course relation to the scale: for instance, but locating a settlement by the location of its oldest church is precise (because we are at settlement level), while locating a house by the location of the settlement it is in is only approximate (because we are geocoding a house, and thus are at house level).

If your data transformation pipeline counts on imputing missing coordinates also from superordinate or even nearby locations, it is advisable not to create artificial precision. For instance, if you have a house, but don't know where within a settlement it was, do not attach coordinates of the settlement to the house, but rather declare that this house - SOE - this settlement.

Another optional thing you might want to add esp. if the localisation is approximate is the source of knowledge - we call it epistemic source. See screenshot above: it says that the source of the coordinates of this location, which happens to be a region, is the coordinates of its administrative centre, rather than other options (e.g., centroid or an actual polyline defining its boundaries).