Castle Slavín, Château with observation tower in Tupadly, Czech Republic

Castle Slavín is an octagonal complex with a hall of national heroes and a 30-metre stone tower in Moorish style, built in 1840 above Tupadly on the site of the Kostelec fortress. It was designed in 1837 by Bavarian architectural painter Wilhelm Gail, who also made a plaster model.

The octagonal hall with its tower was designed in 1837 by Bavarian painter-architect Wilhelm Gail and built in 1840 on the site of the Kostelec fortress, destroyed in the Thirty Years' War. Antonín Veith, owner of the Liběchov estate, planned a larger pantheon-like monument to Czech national heroes but built only one tower before his debts halted the project. The tower served as a public lookout from 1873 to 1946.

The eight-sided hall was meant to honour national heroes from Slavic myth and Czech history. Antonín Veith chose 24 figures with František Palacký and František Matouš Klácel; Ludwig Schwanthaler's Munich studio made eight clay models, cast in bronze 1848–1867 and now in the National Museum in Prague.

The tower has been closed to the public since the mid-20th century, so it cannot be climbed today; it was open only from 1873 to 1946. The grounds now belong to the Buddhist group Samadhi and serve as a meditation centre, so visits depend on the community's arrangements. The site lies on a slope at 250 m above sea level above Tupadly, near the Liběchovka valley.

The tower has been closed to the public since the postwar period, when the area passed to the Research Institute of Soil and the viewing platform was shut. It had served as a lookout only from 1873 to 1946, showing the Polabí lowland and part of the České středohoří.