The moats of Fukuoka Castle were very wide compared with the castles of other "tozama-daimyos" (feudal lords who did not become retainers of the Tokugawa until after the decisive victory of Tokugawa at the battle of Sekigahara in 1600). The moat is about 115 metres (377 ft) wide on the southeast, and on the south, where there are high mounds on both sides of the moat, about 45 metres (148 ft), while to the north of the castle, it is about 70 metres (230 ft) wide on average. The Ohori Moat (Big Moat) has a width of about 600 metres (1969 ft), even after the construction of the Odote Causeway on the west of the Ohori Moat. The single, wide moat surrounding the inner castle is one of the features of this castle and only in few other castles built in the modern period can such an example be seen. The Ohori Moat was originally more than 3 "ken" (5.9 metres in Chikuzen) deep, and as for the other moats, more than 1 ken (2.0 metres in Chikuzen) deep at both sides, and more than 3 ken deep in the middle of the moat.