It was built on a surface hollowed out of a high bank, or elevation, with which the roof of it was on a level.

It was, of course, circular and flat, and the roof drooped, or slanted off towards the rear, precisely in imitation of a cockle-shell.

There was, however, a complete _deceptio visus_ in it.

To the eye, in consequence of the peculiarity of its position, it appeared to be very low, which, in point of fact, was not exactly the case, for it consisted of two stories, and had comfortable and extensive apartments".

There was a paved space wide enough for two carriages to pass each other, which separated it from the embankment that surrounded it.