You can make a team outing interesting by:
Choosing appealing, exciting activities
Involving everyone as much as possible
Conducting surveys to see what your team wants
Providing opportunities for team members to develop friendships
Giving people choices between activities
Setting the outing in an enticing location
By imbuing your team building day with these concepts, you have a higher chance of designing an interesting outing for your employees. Give your team a voice in what they will do during the team building day and a choice in how they would like to enjoy it, and you will see a positive response from employees.