East Germany decided to upgrade the fortifications in the late 1960s to establish a "modern frontier" that would be far more difficult to cross. Barbed-wire fences were replaced with harder-to-climb expanded metal barriers; directional anti-personnel mines and anti-vehicle ditches blocked the movement of people and vehicles; tripwires and electric signals helped guards to detect escapees; all-weather patrol roads enabled rapid access to any point along the border; and wooden guard towers were replaced with prefabricated concrete towers and observation bunkers. 
Finally, if you travel Europe and you see two German groups at a campground, you might easily be able to distinguish them. Eastern Germans usually sleep in tents, while western Germans prefer to travel with trailers. We did not find a scientific explanation, but one might posit that it's rooted in western Germans' longer experience traveling the world. Furthermore, many young eastern Germans couldn't even afford a car under communism. Trying to buy a trailer would have been more expensive and nearly impossible for most eastern Germans. While those in the west were able to explore beyond their borders, eastern Germans remained practically imprisoned by their government for nearly 30 years -- until 25 years ago.