This gate is one of the chief remains of the fortifications which guarded Trocy in the Middle Ages. It will be seen that the strategic importance of the position has at all times been appreciated at its full value. _Having passed through the gate, we take, 100 yards further on to the left, the road that dips into a hollow, on the opposite slope of which stands out the fine farm of Beauvoir._ _We reach this farm by a zig-zag ascent which comes out on the Route Nationale (N. 36). We then turn to the right and go down towards =Gué-à-Tresmes=._ This little place played the part, in relation to the extreme German left, that Trocy played in the centre. It was a heavy artillery position supporting the advanced line of defence. [Illustration: THE BILLIARD-TABLE OF THE CHÂTEAU] At the entrance to the village, on the left side of the road, is a large residence surrounded by a park. It was occupied by the Germans and converted into a field hospital. In order to make room rapidly, the furniture was flung outside. It was thus that the billiard-table was found in the park. A soldier who was evidently a lover of fresh air used it as a shelter. On the opposite photograph can be seen a fish-kettle which did duty as a basin: frequent washing being indispensable during those hot September days. The façade shown in the view is the one which faces the road. [Illustration: PERSONAL BELONGINGS LEFT AT GUÉ-À-TRESMES BY THE GERMANS] A certain number of German wounded died in the hospital and were buried in the garden; their belongings were left behind at the time of the retreat, as shown in the opposite photograph. This retreat must have taken the occupants unawares, for a meal was on the officers' table when the French troops entered the château. _At the cross-roads, about 300 yards beyond the château, go to the left along the Thérouanne. 200 yards further along this road_ is seen (on the right) the place where a group of German artillery was hidden. Well-screened in the hollow shown in the view below, several heavy batteries, for a long time out of reach of the 75's, made extremely difficult the advance of the French right on the Plateau of Chambry-Barcy. They also hampered the left, of the British army and the 8th French Division on the left bank of the Marne. In the course of this tour, we have already seen several examples of the German battery positions. Wherever the ground allowed of it, the guns were placed in a hollow, visible only to aerial observers. Telephones linked them up with the posts established on the ridges whence the firing was directed. _Returning to the Route Nationale, turn to the left towards Varreddes._ On both sides of the road, which was their main way of retreat, the Germans had made lines of defence: trenches were dug and furnished with machine-guns, and light batteries were established as supports.