sentences:  The so-called "Limes Britannicus" is perhaps the best example of the ultimate "limes" - like the Great Wall of China, it was an attempt to construct a continuous man-made fortification along the length of an entire border, a massive undertaking.However, it is not correct to interpret other "limes" in the same way or to view the "limes" as an impenetrable barrier.Other limes would not have had a continuous man-made fortification for the entirety of their length.