The chapel over the well, also known as the Assumption Well with Chapel, was built in the late 17th century over a spring discovered in 1644 at the northwest corner of the Assumption Cathedral. This building is a vivid example of Moscow Baroque. The miniature centralized structure with a tiered design is made of brick, and its rich exterior decoration is created from glazed ceramics and white stone. The composition of the building consists of a square base and three diminishing octagons, the upper ones serving as the drum of the dome. The decor is characterized by developed plasticity, especially lavish in the first tier, and includes window frames, columns, and cartouches made of carved stone and precious majolica. All tiers are open to the interior, giving the space dynamism. The wall paintings in oil and icons date back to the 19th century.