I am setting up some lessons for students to work with Real-World data. Sometimes I want to ask questions using data that are not (yet) available from the Wolfram Knowledge base. For example instead of using the Eiffel Tower as a Geolocation, I want to use a local place like as the Amsterdam Dam Square. Is there a way to put this in in a way similar to built-in entities, so I can use the same syntax and algorithms to calculate with? (Another example: I could not ask students to compute the weight of an elephant divided by the weight of a human (since that weight is missing. Strange enough I can get a proper answer for this from Wolfram Alpha ...). Any suggestions on how to do these elegantly?

Ted