Having now visited the boundaries of the Roman Empire in Britain and Germany I must say that the British wall is much more visible, and accessible thanks to the AD122 bus. Saalburg is indeed an interesting reconstructed fort in a pleasant forest location on a hilltop. I reached it by bus from Bad Homburg. From the fort I walked downhill through the forest passing several marked watchtower foundations along the way, to reach Saalburg station.

Near Neuwied on the Rhine I found some excavations of Roman Baths in Niederbieber, and a reconstructed watchtower on a hilltop in Oberbieber. Both were reached by bus # 101 from Neuwied.

In Miltenberg on the Main river there is an interesting museum displaying a number of Roman artifacts found along the Limes in that area.

In Aschaffenburg I visited the Pompejanum, a reconstructed Roman villa.

Near Konigstein in the Taunus I visited Kleine Feldberg, an excavated fort and bathhouse up a track from the Rote Kreutz bus stop at Glasshutten.

There are many other locations worth investigating listed on the Limesstrasse website, but they recommend travelling by bicycle if you want to travel the whole distance.