Need a good Gate Lock

Hello,
My grandparents farmhouse was recently robbed. No one lives at the house but it is where we all have "get togethers".
They went through the front gate which has no lock. Can any one suggest a good lock, or a way to "beef up" the old gate and add a lock. The gate is home-made, it basically consist of two swinging pipes hinged on the post and a solid metal bar that slides in the middle to hold it closed.
Any help would be good. We are also about to add video surveillance.

Thanks [img]/forums/images/icons/confused.gif[/img]