Tower of Osaka Castle
Toyotomi Hideyoshi, who unified the country during the Azuchi-Momoyama period (1568-1600), began construction of the tower of Osaka Castle in 1583 and completed it in 1585. The castle was later destroyed during the Osaka Natsu no Jin（summer campaign of Osaka） in 1615, but was rebuilt by the Tokugawa Shogunate in 1626. However, the castle keep was destroyed by lightning in 1665. In 1931, the castle tower of the Toyotomi period was reconstructed with donations from Osaka citizens.
Very impressive and well worth a visit.