After a time all these shallows and banks became well matted together by
the growth of weeds, of willows, and flags, while the tide, ebbing lower
at each drawing back, left still more mud and sand. Now it is believed
that when this had gone on for a time, the waters of the river, unable
to find a channel, began to overflow up into the deserted streets, and
especially to fill the underground passages and drains, of which the
number and extent was beyond all the power of words to describe. These,
by the force of the water, were burst up, and the houses fell in.

For this marvellous city, of which such legends are related, was after
all only of brick, and when the ivy grew over and trees and shrubs
sprang up, and, lastly, the waters underneath burst in, this huge
metropolis was soon overthrown. At this day all those parts which were
built upon low ground are marshes and swamps. Those houses that were
upon high ground were, of course, like the other towns, ransacked of all
they contained by the remnant that was left; the iron, too, was
extracted. Trees growing up by them in time cracked the walls, and they
fell in. Trees and bushes covered them; ivy and nettles concealed the
crumbling masses of brick.

The same was the case with the lesser cities and towns whose sites are
known in the woods. For though many of our present towns bear the
ancient names, they do not stand upon the ancient sites, but are two or
three, and sometimes ten miles distant. The founders carried with them
the name of their original residence.

Thus the low-lying parts of the mighty city of London became swamps, and
the higher grounds were clad with bushes. The very largest of the
buildings fell in, and there was nothing visible but trees and hawthorns