Starý Světlov, Medieval castle ruin in Podhradí, Czech Republic.

Starý Světlov is a medieval castle ruin located in Podhradí within the Zlín Region of the Czech Republic. The surviving structure features Gothic stone walls and tower remnants positioned on elevated terrain overlooking the surrounding landscape.

The castle was first mentioned in 1275, when a certain Heřman of Světlov is recorded; by 1360 it belonged to Albert of Šternberk. In 1423 King Sigismund held it and passed it to his wife Barbara of Cilli, whose burgrave was the robber knight Pankrác of Liptovský Svätý Mikuláš. Damaged in the Bohemian-Hungarian wars of 1469–1470, it was abandoned by 1517.

The castle's original name Světlov passed to the new castle built above Bojkovice in 1480, which became Nový Světlov while the older site was called Starý Světlov. The Landštejn brothers moved there in 1490, and by 1517 the old castle was recorded as deserted.

The ruins are accessible throughout the year by following marked hiking trails that link other historical sites in the Zlín Region. Visitors should wear sturdy footwear since the terrain is uneven and trail conditions vary depending on the season.

The castle was probably abandoned after the Landštejn family moved to a new castle of the same name above Bojkovice in 1490. The deserted ruin was later quarried for building stone, with up to 2,500 cubic metres of masonry removed from the second half of the 18th century.