Formerly on this same height stood a castle, but this has been so
completely broken down that nothing remains of it but a few
substructures and its well.

Troo was at one time a walled town, and as it was the key to the valley
of the Loir, was hotly contested between the English and French during
three hundred years, and later, between Catholics and Huguenots. The
place was besieged by Mercader, the captain under Richard Coeur-de
Lion, who had flayed alive the slayer of his master under the walls of
Caylus, although Richard had promised him immunity. Here Mercader met
his death, and was buried under a mound that is still shown.

But what makes Troo especially interesting is that the whole height is
like a sponge, perforated with passages giving access to halls, some of
which are circular, and into store-chambers; and most of the houses are
wholly or in part underground. The caves that are inhabited are staged
one above another, some reached by stairs that are little better than
ladders, and the subterranean passages leading from them form a
labyrinth within the bowels of the hill, and run in superposed storeys.
In one that I entered was an oven, with a well at its side. A little
further, in a large hall, a circular hole in the floor unfenced gave
access by rope or ladder to a lower range of galleries. Any one
exploring by the feeble light of a single candle, without a guide,
might be precipitated down this abyss without knowing that there was a
gaping opening before him. A long ascending passage, with niches in the
sides for lamps, leads to where the fibres of the roots of the trees on
the mound above have penetrated and are hanging down. It is said that
the gallery led on to the castle, but since this latter has been ruined
it has been blocked. In the holes whence flints have dropped spiders