Zámek Kostrčany is a cultural monument located in the village of Kostrčany near Valče in the Karlovy Vary District. This Baroque castle, protected since 2001, has a rich history dating back to the late medieval period. Initially mentioned as a manorial estate in 1387, it evolved through various ownerships and architectural styles, culminating in its transformation into a Baroque structure in the 18th century. Despite its historical significance, the castle is not open to the public.

The early history of Kostrčany's manorial estates remains somewhat obscure. The first documented mention dates back to 1387 as a farmstead, which might have included a noble residence. By the late medieval period, there were at least two such residences in the village, though it is unclear if they correspond to the Gothic and Renaissance fortifications noted in the sixteenth and seventeenth centuries. It is assumed that an older manor existed possibly outside the village.

In 1521, Asman Štampach ze Štampachu acquired Kostrčany for 200 Czech groschen from Václav Valečského z Doupova. Shortly thereafter, he expanded his holdings by purchasing additional lands and properties in the area. By 1571, Arnošt Hasištejnský z Lobkovic owned the estate, but it was sold to Vít z Hartenberka just two years later. The castle's fortunes changed dramatically during the Bohemian Revolt of 1618-1620 when Vít z Hartenberka lost his holdings due to his involvement in the uprising. In 1623, Jan Hegner z Rösselfeldu purchased the estate after it was confiscated.

The original Renaissance manor house no longer exists; it was replaced by a Baroque castle in the eighteenth century. The current structure is a single-story building with a mansard roof, typical of Baroque architecture. It features an oblong plan measuring 18 by 11 meters and retains one vaulted room on the ground floor. The eastern and northern facades are adorned with flat pilasters and banding, while the windows in the lower level have cornice lintels.

Over time, Kostrčany changed hands several times. In the eighteenth century, František Karel Clary-Aldringen acquired the indebted estate from Karl Maxmilián Lamotte von Frintrop. The estate was later owned by Adam František Hartig and subsequently passed through various owners, including Ludvík Hartig, Antonín Josef Clement, and Karl von Nikelsberg. By 1793, Ignáci Schreitter had purchased the estate, followed by a succession of private owners until it was nationalized after World War II.

Today, Zámek Kostrčany stands on the edge of an agricultural estate near Valče. Although not open to the public, its historical significance and architectural features make it a point of interest for those exploring the region. Accessible via cycling route number 2152 from Blatna through Lubenec to Valče, the castle offers a glimpse into the past and invites visitors to appreciate its storied history.

Zámek Kostrčany is not just an architectural relic but a testament to the dynamic history of Bohemia. Its transformation from a medieval manor to a Baroque castle reflects broader historical shifts in ownership and style. For those interested in exploring the rich tapestry of Czech heritage, a visit to this site offers valuable insights into the region's past.