We are using CiviCRM 4.6.28 on current Joomla version. As we are using the training location in the title already we would like to remove the display of the location column as it is irritating if it shows (not available).
You haven't said which page you are referring to but I'm guessing that this is the public HTML listing of events. If so, the output is controlled by this template:
You can copy this to create a custom template and edit it to remove the location column.
Read more about customising templates here: Page Templates