Located within the main city park among its ancient oak trees, is the Trinity Cathedral which now serves as the eparchial cathedral of the Kaluga and Borovsk Eparchy. It was built between 1786 and 1819 in the classical style with a pillar-less building topped by a large dome with a 17 metre diameter and attached to a four-tier bell tower. The cathedral was closed in 1924, damaged in the war and then returned to the Church in 1991. After undergoing restoration work the cathedral was re-consecrated in 1999.