1716-1720, architect J.-B. Le Blond, J. Braunstein, N. Michetti
The Upper and Lower grottoes, being the architectural center of the Peterhof Grand cascade, were built according to Peter I's idea. They are faced with tufa, decorated with fountains, marble and a gilded sculpture. The facade of the Large grotto is pierced by the five tall archways, decorated by gilded mascarons. On top of this grotto there is a terrace, leading to the Small grotto. The marble balustrade with figures of two bronze gilded Tritons, serves as a borderline between the grottoes.
The Lower grotto is a large hall with a high ceiling. The magnificence of the hall, is highlighted by the marble sculpture of Peter's time, the work of the Italian master, Pietro Baratta; and the gilded galvanoplastic copies of the antique originals, made in the XIX century.
The hosts and the visitors of Peterhof, enjoyed their time in this almost unreal "resting retreat". In the Lower grotto, Peter was planning to install the trick-fountain - the "splashing table" and the "water curtains", but the idea was implemented only after the Tsar's death. The glasses with drinks and the fruit vases, were placed in the center of the table. That looked so appetizing, that anyone would like to try them. But should some guest reach out to the vase, these water jets would spring up from the little tubes, laid by the sides of the table, spraying everyone around. A great variety of similar water amusements, was wide spread in the XVIII century. At the exit of the grotto, one more surprise was awaiting the guests - a thick water curtain, that was blocking the path.
Until our days, the Grand cascade with the grottoes, preserved the integrity of architectural composition and artistic decoration. When transitioning from the Upper to the Lower grotto, one can see the authentic brickwork of Peter's time, the pipes, directing the water to the fountains of the Grand cascade, the scheme of the fountain conduit - a unique monument of the hydraulic art of the XVIII-XIX centuries. The exhibition, presented in the Grotto, introduces to the works of the fountain masters of the past, their materials, that the pipes were manufactured in the XVIII-XIX century, authentic details of the fountains' sculptural decoration. Once one gets to the area, decorated with the "Basket" fountain, he appears at the very center of the magnificent aquatic action - of the Grand Cascade operation. This opportunity is available only by visiting the grottoes.