The king, shocked at what was as unhealthy as it was disgusting, sent for the burghers and provost of the city, and ordered that all the thoroughfares and streets of Paris should be paved with hard and solid stone, for this right Christian prince aspired to rid Paris of her ancient name, Lutetia (Mud-town)." It is added that, on hearing of so good a resolution, a moneyed man of the day, named Gerard de Poissy, volunteered to contribute towards the construction of the pavement eleven thousand silver marks.
Nor was Philip Augustus less concerned for the external security than for the internal salubrity of Paris.

In 1190, on the eve of his departure for the crusade, "he ordered the burghers of Paris to surround with a good wall, flanked by towers, the city he loved so well, and to make gates thereto;" and in twenty years this great work was finished on both sides of the Seine.

"The king gave the same orders," adds the historian Rigord, "about the towns and castles of all his kingdom; "and indeed it appears from the catalogue of M.Leopold Delisle, at the date of 1193, "that, at the request of Philip Augustus, Peter de Courtenai, Count of Nevers, with the aid of the church-men, had the walls of the town of Auxerre built." And Philip's foresight went beyond such important achievements.

"He had a good wall built to enclose the wood of Vincennes, heretofore open to any sort of folk.

The King of England, on hearing thereof, gathered a great mass of fawns, hinds, does, and bucks, taken in his forests in Normandy and Aquitaine; and having had them shipped aboard a large covered vessel, with suitable fodder, he sent them by way of the Seine to King Philip Augustus, his liege-lord at Paris.
King Philip received the gift gladly, had his parks stocked with the animals, and put keepers over them." A feeling, totally unconnected with the pleasures of the chase, caused him to order an enclosure very different from that of Vincennes.