[4K UHD] Masuda Iwafune "Rock Ship" | Asuka Village, Japan | 2023

A short hike uphill led us to Masuda no Iwafune, which translates to Rock Ship of Masuda.
It is not clear when or why this was carved, though the sign in front of the massive stone has some suggestions (shown @ 06:50 in this video):
"Historic site Iwafune. A huge stone structure made of granite located near the top of Mt. Iwafune. This stone structure has a trapezoidal shape measuring 11 metres long from east to west. 8 plates from north to south, and 4.7 metres high on the north side. A shallow groove-like cut is provided. At the top, two square holes are drilled in the east and west at an interval of 1.4m in this groove. The hole is 16 square metres from east to west, 1.6m from north to south, but the lower half is a grid-like shaping can be seen while rough-cut. There is a theory that it is the base of Masuda Pond, which was built in this area since ancient times, but there is also a theory that the top flat surface is rotated 90 degrees to form a horizontal stone box, another theory is that it is the foundation of an astronomical observatory, and another theory is that it is a watchtower. There is a theory - purpose is not clear, the grooves and holes in the upper flat surface were planned in the Goryeo scale, and the granite processing technology was common to that of the tumulus of the end of the 19th century. It is the largest among the peculiar stone structures distributed in the the region." - Kihara City Board of Education

Estimated at 800 tons, now surrounded by bamboo forest.
There was a dead piece of bamboo on the ground nearby, which went approximately 2.5' into the two holes on top of the stone. As shown, there is a lot of fallen plant debris and water occupying theses spaces which reportedly go all the way to the ground.
As per the warning sign at the start of the path, watch out for wild boars!

District: Takaichi
Prefecture: Nara Prefecture
Region: Kansai

00:00 trail head
02:00 hiking
03:18 first sight
04:44 on top
06:50 description