Originally a fortification on this site was built by the Numata in defense of Numata Castle. The present fortifications date to Sanada Masayuki who fortified them to launch his attacks on Numata Castle. As an ally of the Takeda, Sanada Masayuki took control of the area by taking Iwabitsu Castle, Nagurumi Castle and finally Numata Castle in 1580. This area was heavily disputed between the Sanada and the Hojo until 1589 when Hideyoshi ended hostilities by giving the area, including Nagurumi Castle, to Sanada and the remainder to the Hojo. This decision did not sit well with the Hojo commander Inomata Kuninori who attacked and took Nagurumi Castle in late 1589. This was the famous spark that set off Hideyoshi's campaign to end the Hojo. Hideyoshi defetaed the Hojo the following year (1590) thus unifying all Japan. The Sanada were given Numata castle and Nagurumi was abandoned.
The structure and position of Nagurumi Castle is really interesting. It is built atop a steep mountain overlooking the Tone River. Across the river and about 5km away is Numata Castle. If you were to attack Nagurumi Castle from Numata or across the river it would be almost unassailable given the steep cliffs protecting it. However, from the opposite side, the castle is actually more like a flatland castle. If you visit the castle I recommend you pay attention to this unique aspect too. I biked from Jomokogen Station to Nagurumi Castle and then on to Numata Castle. It's also interesting that Numata Castle is built atop a mountain across the other side of the river. I can just imagine the rivals looking out over the Tone River valley at each other.
You could also walk from the Jomokogen shinkansen stop. It's just a few minutes more walking but it's mostly flat and would allow you to stop by Ogawa Castle along the way. If you visit Nagurumi Castle, you should also visit Numata Castle to take in the full importance of the history in this area.
There is a small visitor center where you can get a map. There are no artificats but they have some displays related to the castle and information about local historical sites. I didn't note the open hours/days but it was open from 9am.
|English Name||Nagurumi Castle|
|Year Founded||around 1492-1501|
|Castle Condition||Ruins only|
|Designations||Next 100 Castles, Prefectural Historic Site|
|Historical Period||Pre Edo Period|
|Access||Gokan Sta. (Joetsu Line); 40 min walk|
|Visitor Information||Park, open any time|
|Time Required||45 mins|
|Location||Minakami, Gunma Prefecture|
|Coordinates||36° 40' 9", 138° 59' 27"|
|Visits||Apr 29, 2013|