Research always comes first. Of course you always get the best impression, if it is at all possible, on the spot, at the original scene. Witnessing a fizzing, bubbling geothermal field, which is giving off the stench of rotten eggs or sulphur, will always be important as an invaluable experience for the subsequent presentation. In many cases, however, when you consider the presentations of times long past, the study of various sources from literature, museum exhibitions, etc. plays a dominating role.