North of Arzbach the land lifts out of the Lahn valley and into the Westerwald, and the Roman frontier did the same. The Limes here is a section rather than a single tower, a line where a ditch, bank and a string of watchtowers once ran across the ridge. It is a faint thing now, a low earthwork under trees, but you can follow it on foot if you know where to look, and the local Limes trail marks the way. The nearest villages, Arzbach and Kadenbach, are small and quiet, with only a couple of thousand people between them.
On a motorcycle the area is a gentle tangle of lanes and wooded hills. The roads rise out of the valleys in a series of shallow switchbacks, and on the ridge they flatten into long, easy bends between fields. The surface is generally good, with only the odd patch of gravel, and on a weekday the traffic is light. Spring and autumn are the best times, when the woods are fresh or coloured and the air is clear enough to show the line of hills rolling away toward the Taunus.
Services are in Bad Ems, about five kilometres away, a spa town of nearly ten thousand people with fuel, restaurants and a long riverside promenade. The Lahn valley below has the most dramatic scenery in the area, with steep wooded slopes, old railway viaducts and the occasional castle, and it makes a pleasant contrast to the plateau. If you have time, ride down to the river for lunch and climb back up again by a different road, and you will come away with a feel for how the landscape fits together.
What I like about sections like this is that they tell you something simple. A frontier is not a wall around a country, it is a line drawn across a hillside and patrolled by bored men, and it only becomes monumental when we look back. Take a quiet minute among the trees, and let the thought settle.