The opening to the Lucas Cave is very massive, and has a rather steep fall of about 12 feet from the pathway to the floor of the cavern. The entrance is about 30 feet wide and 25 feet high. The roof of the portico is ornamented by rocks, which in shape and colour appear to be in keeping with the gloomy-looking tunnel beyond. The overhanging masses are honeycombed and convoluted in a remarkable manner, and thin off to points like stalactites. The curved, tapering forms are in groups of various dimensions, drooping in folds like those of loosely-fitting garments. They represent not "formation," but the original rock, out of the crevices of which the softer portions and earthy substances have been extracted by the ordinary operations of Nature. To the left of the archway is a bulky convoluted pillar, rising from the surrounding blocks and boulders to the uppermost part of the portico, and to the right of the archway is a fine piece of stalagmite formation about 10 feet in height. In the centre, immediately behind it, is a large stalactite, and near by an extensive patch which looks like conglomerate of lime and pebbles. On the outer walls are flowering shrubs and creeping plants, including one which bears a strong resemblance to the climbing fig (_Ficus stipulata_), which clothes with pleasant verdure many an ugly wall in and about Sydney. The rock colouring is especially fine and beautifully shaded all the way from the broad daylight to the beginning of the interior blackness, which is somewhat sharply defined by a fringe of stalactites like the vertical bars of a portcullis. The immediate entrance to this cave is begrimed with dust. A few yards onward there is an iron gate. The guide opens it and carefully locks in his visitors, who light their candles and proceed by a downward path. The descent is about 80 feet, partly by steps cut zigzag fashion, and then on a sloping floor covered with _débris_. There is a marked difference in the temperature, which is many degrees higher than that of the outward air, and several degrees warmer than the interior of the Arch and Nettle Caves. Small flies surprise the excursionists by the suddenness of their appearance, and by the narrow limits of their _habitat_. They live in the zone between daylight and darkness. In the region of perpetual night the only signs of animated nature are clusters of bats. The lighted candles serve to make the surrounding darkness more pronounced.