All the strongholds of the Mound-Builders rise near abundant watercourses, and the best proof that can be given of the intelligence which guided their constructors in their choice of sites, is the fact of the number of flourishing cities such as Newark, Portsmouth, Cincinnati, Saint Louis, Frankfort, and New-Madrid, etc., which were built upon the ruins of various earthworks. It would take us too long merely to enumerate all the ancient fortifications still existing in North America. Moreover they all resemble each other so much that the description of a few of them is really all that is needed to prove their importance. Fort Hill (Fig. 5, p. 39) rises from an eminence overlooking a little river called Paint Creek; the walls vary in height from eight to fifteen feet, and exceed thirty feet in thickness.26 Several doors facilitate entrance, and one of them leads to a square _enciente_, the walls of which have been almost entirely destroyed. This enclosure probably contained the homes of the people, which may have been mere cabins of adobes or sun-burnt bricks, or buts covered with rushes, interlaced branches, or the skins of animals; on this point we are reduced to guesswork. In the centre of the principal enclosure can be made out, in almost every case, several much smaller enclosures, each containing in their turn one or more mounds. Some think these were consecrated to religious rites, but this is a mere conjecture, for nothing is really known of the form of government or of the religion of the Mound-Builders. Forest trees have grown up on these abandoned ruins, succeeding other vegetable growths; the huge girth of the decaying trunks proving their longevity. Man, impelled by motives we cannot fathom, had abandoned the districts where everything bears witness to his power and intelligence, and the vigorous vegetation of nature once more has it all its own way.