Mittelbastion (Werk IV)

On the Blau river, at the protruding angle of Ulm's middle city front, stands the Mittelbastion, also known as Werk IV. Built between 1840 and 1855, it belongs to the Bundesfestung Ulm, once ranked among Europe's largest fortifications. Today it sits in a shaded green corner between paths and trees, with the water still running past its front.

At the centre of the work rises an octagonal Montalembert tower, a massive reduit serving as an inner stronghold. If the outer lines ever fell, the garrison would withdraw here and hold out. A second flank stands on the left shoulder, a ditch caponier on the right. Their geometry threw crossfire across the ditches and controlled an attacker's every move. The river took a share of the defence as well: engineers could dam it and flood the whole ground in front. A direct attack across that flooded ground became a far harder proposition. The bastion was less heavily fortified than some neighbouring works, yet its position combined sight, protection and control.

Moss takes hold on the masonry now, and little stirs between the walls. The forefield that once lay under water is now green, open space you cross on foot. The tower built to hold out last holds only shade and quiet.