From Shiga Prefecture.
Lake Biwa covers 669.26 km², about one sixth of Shiga Prefecture. It is 63.49 km from north to south, and 22.8 km across at its widest and 1.35 km at its narrowest. Its shore is 235.20 km long.
The lake has a small southern basin and a large northern basin. Their areas are in the ratio of 1 to 11.
The average depth is about 41.2 m: about 4 m in the southern basin and about 43 m in the northern basin. The deepest point is 103.58 m.
The lake holds 27.5 billion m³ of water. That is about 11 years of the water that the 14.5 million people of the Yodo River basin, who use water from the lake, use each day.
Most lakes fill up with sand and mud and disappear in about 10,000 years. Lakes more than 100,000 years old are rare.
Lake Biwa has been in its present place for at least about 400,000 years, and the first ancient Lake Biwa goes back about 4 million years. In the world, there are only about 20 ancient lakes, over 100,000 years old and with species found nowhere else. In Japan, Lake Biwa is the only one.
More than 1,700 kinds of water animals and plants have been reported in Lake Biwa. More than 60 of them are endemic species, found only in Lake Biwa.
There is no single right answer. Talking it over with someone at home is a good way to learn.