The communiqués of 1915 mention many feats of this kind, and to-day the traces which still remain of this ferocious struggle attest its extreme violence. On each side of the Albert-Bapaume road, opposite La Boisselle village, huge craters form an almost continuous line. [Illustration: BRITISH GRAVES IN THE GREAT MINE CRATER AT LA BOISSELLE.] The largest crater lies on the right. It has a diameter of about 200 feet and a depth of 81 feet. British graves lie at the bottom _(photo opposite)_. This mine warfare procured no appreciable advantage to either side. Fresh defences were immediately made on the edge of or near the new craters, in place of those which had been wiped out, and the front line remained practically unchanged until the offensive of the Somme. On July 1, 1916, the British rushed the German trenches in front of La Boisselle and Ovillers, giving rise to a fierce engagement. After two days of incessant fighting the whole of La Boisselle village was captured. A battalion of the Prussian Guard made a desperate resistance at Ovillers, the survivors--124 men and 2 officers--surrendering only on July 17. [Illustration: MINE CRATER AT LA BOISSELLE.] _Leave La Boisselle on the right, and take N. 29._ [Illustration] _Ten yards from milestone "Albert 5 km. 4," take the left-hand road to =Ovillers= (600 yards distant)._ Of this village not a wall remains standing. _The road turns to the left and crosses the village_, in which numerous shelters and military works can still be seen. _Outside Ovillers, on the right, there is_ a large cross, erected by the British in memory of their fallen comrades of the 12th Division. _A little further on, there is_ a British cemetery _on the same side of the road_. _The road turns to the right, then descends steeply to the Ancre marshes. Cross these by the footbridge built by the Army Engineers, to =Aveluy= village on the opposite side._ Of this village, only a few walls remain standing, among which are numerous military works. _On leaving Aveluy, the road crosses the railway. Take the road on the right immediately after._ _Follow the marshy valley of the Ancre upstream._ [Illustration: PANORAMIC VIEW OF THE VALLEY OF THE ANCRE, AS SEEN ON LEAVING HAMEL FOR BEAUCOURT-SUR-ANCRE.] [Illustration: THE ANCRE MARSHES, IN FRONT OF THE RUINS OF AVELUY.] _The road crosses =Aveluy Wood=_, the trees of which are cut to pieces. _2 km. 500 beyond Aveluy, before the fork with the road to Mesnil, there is a_ British cemetery _on the right_. _On leaving the wood, follow the railway to the_ ruins of =Hamel= village. _Before entering_, note the British cemetery _on the left_. Opposite, on the crest of the hill, on the left bank of the Ancre, is =Thiepval Wood=, cut to pieces by the shells. The view of the Ancre Valley from here is most impressive _(photo below)_. The British Operations in the Ancre Sector