Parts of stone walls and gold-plated roof tiles believed to be the ruins of Shigetsu Castle have been discovered at the construction site for a new apartment complex in Fushimi Ward, Kyoto, a private research firm has announced.

Feudal leader Toyotomi Hideyoshi began construction on the castle in 1592, a year after he ended his regency. But it was called a "phantom castle" because it was said to have been destroyed by an earthquake in 1596, and no remnants had ever been found.

Researchers have excavated some 36 meters of stone wall about 0.5 to 1 meter high and 2 meters thick, more than 100 fragments of gold-plated roof tiles, and the remains of a 5- to 7-meter-wide, 2-meter-deep moat, according to Kyoto-based firm Kyoto Heian Bunkazai.