It took me two nights and one day to travel by train from Ulaan Baatar, in Mongolia, to Irkutsk, in Siberia, Russia. It could have taken somewhat less, but the train schedule allows 9 hours for the border procedures in crossing from Mongolia to Russia, even though the actual border check took less than an hour on each side.
When I woke up, we were in Sukhbaatar, Mongolia, a town on the river Selenga. The river is beautiful. In Sukhbaatar it seemed to be flooding.
The train followed the Selenga river all the way until the sun set and I could no longer see. In places, the river was wild and beautiful. We were following the river downstream, so it kept getting bigger.
With 9 hours to spare, I had plenty of time. This is the border post between Mongolia and Russia.
There were many wooden houses across the border, and no ger.
I also went to a market, where I found a type of sour berry called something like kreshovnik. I was told it can be made into jam. It was good, but so sour that I could only eat so much.
At one point, we went past a large lake called Gusinoye Ozero, or Goose lake.
At the north end of the lake is the town of Zagustay, with a huge power plant. The air was very clear, though.
After going past lake Baikal in the night, in the morning of the 22nd I arrived in Irkutsk, on the Angara river.