Lorient lighthouse, Signal tower in Lorient, France

The Tour de la Découverte is a signal tower on the Faouëdic hill in Lorient, not a lighthouse. It is a tapering cylinder of light grey stone, 8.78 m in diameter at the base, with horizontal granite bands and round openings along the shaft. Its 216-step granite spiral stair ends at a ladder to the lantern.

The Compagnie des Indes built the first tower between 1737 and 1744, raising it to 36.7 m by 1748. After lightning strikes in 1751, 1782 and 1784, the royal navy rebuilt it from 1785 to 1786 to plans by Philippe Guillois, fitting one of Europe's first Franklin-model lightning rods. It has belonged to the city of Lorient since 2008.

The tower is a signal tower, not a lighthouse: it never carried a light, which stood instead on the church of Saint-Louis. Its name comes from its role as a lookout over ships returning from the Indies. Since 2021 a 75 kg black steel time ball on a mast drops to mark the port's mean noon, at 14:13:25 in summer time and 13:13:25 in winter.

The tower stands on the Faouëdic hill inside the Enclos du port, 24.6 m above low tide level, and is reached by a spiral staircase of 216 granite steps followed by an 8-rung ladder to the lantern. The hill is wooded and the tower is owned by the city of Lorient since 2008.

The tower never had a light: the harbour light stood in the church tower of Saint-Louis, aligned with the entrance channel. Instead, from 1882 a time ball dropped at mean noon, and a 75 kg stainless-steel ball on a mast, fitted in 2021, still marks port noon at 14:13:25 in summer and 13:13:25 in winter.