Descending 12 steps, and passing through a tunnel five feet six inches by two feet, the visitor stands at the junction of the right and the left hand branches of the cave. Here formerly the passage was only 14 inches by 15 inches. The larger opening was made by blasting, and the material blown from the solid rock has been packed away in recesses at the side of the hall, which, at the junction of the two branches, widens out considerably, but does not present any specially interesting features. The right hand branch runs north-west, and the left hand branch runs south-west. Taking the south-west branch first, after travelling about 10 yards the visitor comes to "The Gravel Pits," which he reaches by ascending a mound with 13 steps. There are two pits of gravel. One of them is about 12 feet deep and the other about 15 feet. In the rocks overhead are bones distinctly visible, owing to the earthy matter having fallen away from them. Some of these bones are large. There are shelving rocks about six feet from the floor. The sides of one of the Gravel Pits are oblique, but the other pit, which is railed off, is round and perpendicular. It could hardly have been more symmetrical had it been made by a professional well-sinker. This spot, although perhaps uninteresting to a mere sight-seer, cannot fail to attract the attention of geologists. Ascending two flights of stairs with 14 steps each, the excursionist attains a height of about 40 feet above the Gravel Pits in a north-westerly direction. Between the two flights of steps the ground is sloping, and the walls hold a considerable portion of drift, the pebbles of which are large and tinged with oxide of iron. This passage leads to the Margherita Cave, and from it a tunnel branches off towards the "Architect's Studio." This is a very pretty vestibule, about 30 yards in length, and bearing south-east. At first it rises several feet by steps, and later on there is a descent of five steps through masses of stalactites, and past a beautiful pillar. [Illustration: THE ARCHITECT'S STUDIO.] THE ARCHITECT'S STUDIO.