The word Hufeisenturm means horseshoe tower, and it is the sort of detail that tells you about the Roman world when it was under pressure. In the fourth century, with raiders crossing the Danube more often, the Romans rebuilt many of their frontier forts with a new style of defence. Instead of square corner towers, they built tall towers in a U shape that projected out from the walls, giving archers and artillery a wider field of fire. The east tower at Pochlarn, the Roman fort of Arelape, belongs to that period.
Arelape stood at an important spot, where the Erlauf river meets the Danube, and soldiers there controlled river traffic and the road along the south bank. The fort was part of a line that ran through what is now Austria, one of several sections of the Danube Limes listed by UNESCO in 2021. Today the walls lie mostly under fields and houses, but traces of the horseshoe tower have been uncovered, and archaeologists use them to understand how the fort was rebuilt in its later years.
The area is a gentle one for riding. The Danube valley here is wide and green, with orchards and fields, and the B3 runs through small villages with churches and inns. Klein-Pochlarn lies just across the water, and a look back at the town from the far bank is worth the short detour. Traffic on the main road is moderate on weekdays but can build on sunny weekends. Clear days give good views, and autumn mist adds mood.
Fuel is available in Pochlarn, though it is a small town, and bigger supply is found in Melk a short distance away. Eat at one of the inns along the river, where local freshwater fish such as zander and trout often appear on the menu, with a glass of Gruner Veltliner. The cycle path along the river brings in many visitors in summer, so expect to share the road with them. If you have time, ride up into the hills behind the town for a view across the valley.