When the new Court Theatre was completed in 1817, a more direct link with the Palazzina della Meridiana (Sundial Building) was required. To this end, the entrance to the Giardino di Annalena (Annalena Garden) onto Via Romana was renewed and a broader space, an exedra large enough to allow carriages to travel, was created. During the works, which included the construction of the Assistant's house (now Annalena Building) and the entrance gateway, this grotto was created. Known as Grotto of Adam and Eve, it takes its name from the eponymous group of sculptures by Michelangelo Naccherino which was relocated to the grotto after being transferred from its original position just in front of the Knight’s Rampart (Bastione del Cavaliere), where the Lavacapo sculpture currently stands.
The construction of the Grotto, located in line with the entrance gateway, and the development of its surrounds were the work of Giuseppe Cacialli. It features a rectangular open side divided into three spaces separated by two Doric columns. In the basin there is a rectangular plinth which supports the sculptures of Adam and Eve. On the interior wall of artificial rock, three large masks were added by Ottaviano Giovannoni. The half-sphere dome boasts Grotesque decorations and shells set in geometric frames.