This is Takeda Castle. It's located in Hyogo Prefecture. In the sky.
As website JCastle points out, the mountain top castle is now ruins, but it's amazing that in the 15th century, they got all those rocks up the mountain, to 354m above sea level.
No wonder the castle is called Japan's Machu Picchu and compared to the famed Studio Ghibli anime Castle in the Sky.
The castle was abandoned in 1600, after its last lord committed seppuku.
According to Japan Realtime, more and more people are visiting the castle each year. The grounds, JCastle notes, are in good condition, and thankfully, tacky fences haven't been put up everywhere, which would have ruined the visual tableau.
Here are views from the castle. Stunning, no?
The best time to go, apparently, is early in the morning to watch the fog cover the mountain, making the castle look like it's floating in air. Autumn is also popular, because the leaves are changing. If you do happen to visit the castle, be aware that the weather can be unpredictable.