Under the Classical Pavilion, there are two grottos. One of them is called the Three-Arch due to its three arch entrances, while the other is known as the Large or Single-Arch. The word "grotto" comes from Italy and refers to artificial caves dug into the slopes of rivers and ravines, serving as unique park pavilions. Inside the grottos, the air temperature is always a few degrees lower.

In Kuzminki, there are no sharp changes in relief, but during the construction of the grand courtyard and leveling of the area, a slope was formed on the bank of the pond, where the grottos were created. Their construction took place between 1811 and 1830. The first date is associated with the beginning of the development of the English park, where such romantic compositions fit well into the overall landscape. The grottos are adorned with decorative masonry, alternating rows of smoothly hewn white stone and taller rows of porous decorative stone. The second date, 1830, is mentioned in documents regarding repair work in the grottos. At this time, the park's plaster figures were also restored, which may have originally stood in front of the Three-Arch grotto. The extreme arches have pedestals where decorative figures likely once stood.

The Large grotto was used for theatrical performances during holidays. The shows were sometimes staged by the hosts and their guests. Interestingly, if you draw an axis through the center of the Music Pavilion, it will intersect the Large grotto, making it a kind of sound resonator.

The grottos were restored in 2006.