By default, on the activity detail page, there is no way to get the list of projects.
It is hard to explain each time again to new users, that they are supposed to go to their profile=>my Preferences => Activity Navigation Column => Edit and then include the 'project management' block in order to get a menu like this:
Is there any reason why projects are not in the activity menu by default? Are there many use cases where a user would need access to an activity detail page, but would never be interested to drill down to the list of projects in that activity?
Customer support service by UserEcho