The middle of the Wicklow plateau is a strange place to try to describe, because it is mostly absence. Valleymount to the west and Rathdrum to the south are the nearest named places, and both are a long way off by road. You are, for practical purposes, alone with the weather.
Descending toward Glenmacnass is the best part. The road tips down into a glacial valley, a classic U shape carved by ice, and the waterfall that tumbles beside the road in the upper valley is one of the few places on the route where almost everybody stops. Pull off carefully; the lay-by is small and the road above it has fast, blind approaches. After rain the falls are loud enough to hear through a helmet, and in a dry August they dwindle to a rope of white water on dark rock.
The Military Road was built in the aftermath of the 1798 rising to give the army access to the glens where rebel bands had hidden. Construction took years, and the line it follows through the mountains is deliberately direct, which is why it feels more like an engineer's decision than a traveller's. Barracks were placed at intervals, and a few survive in one form or another. The rebels lost the war, but the road gave the area its first real link to the outside world, and the glens slowly opened.
Riding it is easy but never dull. Corners are open and readable, the gradients are moderate, and the surface changes from smooth to patched without warning, usually just where a stream crosses underneath. In cold weather and low sun, black ice can sit in the shaded hollows long after the rest of the road has dried, so be cautious in the early mornings of spring and autumn.
For fuel and food, Rathdrum is the nearest small town, and Kilquade, farther east, is a bigger settlement. Laragh, down the valley, has cafes and a bakery-style stop where walkers and riders swap weather reports.