At one minute you are struggling for space, and suddenly you emerge upon a Gothic-looking hall, full of gracefully pendent stalactites.

Again you proceed along corridors, at one time lofty, at another threatening your head, if pride do not give way to humility.

Then you come to rivers, of which there are two.

At one time you are rowing under a magnificent vault, and then, anon, you are forced to lie flat down in the boat, or leave your head behind you, as you float through a passage, the roof whereof grazes the gunwale of the boat.

My guide informed me that there was a peculiarity in these rivers nobody could satisfactorily account for, viz., that the more it rained, the lower these waters fell.