Wellington was doubtless aware that Gneisenau would be slow to take a course that endangered the Prussians. If after all the Prussians were not coming, there was yet time to retreat from an untenable position. Under the pressure of this anxiety, Wellington is said to have spent a great part of the night in riding over to Wavre and back, in order to see Blucher and make sure. Whatever passed at that interview,[80] the duke was satisfied, and on the fateful morning of the 18th, his troops stood to their arms in the stations already assigned to them. The field of Waterloo has probably been visited by more travellers than any other battle-field in the world: but its aspect has been changed in some respects since 1815, so that the description to be given of it will not be found to tally exactly with what is to be seen to-day. Wellington's army was posted on a slight ridge, running about east and west, and occupied a front of over two miles. The ridge is crossed about the centre of the position by the high road from Charleroi to Brussels, and a country road runs along it, a little below the top on the southern side. Less than three miles to the northward the Brussels road enters the forest of Soignies; and Wellington calculated that this would protect him in case of defeat. There were roads enough to withdraw the artillery, &c.; and the forest, being thick but free of underwood, would present no obstacle to infantry retiring, and would assist them in keeping off pursuit. At the extreme western end of the ridge lies a small village called Merbe Braine, somewhat sunk in a hollow: this protected Wellington's extreme right from being easily turned. The front of his right was covered by the château of Hougomont, a good-sized country house with gardens and orchard, enclosed by a wall. This lay down in the valley separating the two armies; and it is obvious that no attack could be made on Wellington's right unless the assailants had first seized this château, while on the other hand their possession of Hougomont would have given them great facilities for further advance. Similarly, in advance of Wellington's left, lay two farms, La Haye and Papelotte, and a little hamlet called Smohain, but the ground gave no protection to the left flank of the position. Close to the Charleroi-Brussels road, near the bottom of the slope lies the farm of La Haye Sainte; this also formed some little protection to the centre. The ground was practically all open, and the slope down into the little valley that divided the two armies before the battle not very steep, but still an unmistakable descent. The slope up the opposite side was at about the same inclination, so that the fronts of the two armies, a little over three-quarters of a mile apart, lay on two roughly parallel ridges. The English ridge was narrow enough for it to be feasible to place the troops, when not actually standing to repel attack, on the reverse or northern slope leading towards the village