Pietrasze
On July 12 and 13, 1941, Nazi killing units (Police battalion 316 and 322) killed about 4,000 Jewish men in a forest north of Bialystok called Pietrasze. The Jews were forced to undress and then stand next to pre-dug graves and shot. A total of 6500 – 7000 Jewish men were murdered in Bialystok region in the weeks after Germany invaded the Soviet Union, June 22, 1941 (Bialystok was then within the Soviet borders).
Current status: Monument (2015).
Location: 53° 10' 11" N 23° 09' 55" E
Get there: Car.
Follow up in books: Arad, Yitzhak: Holocaust in the Soviet union (2009).
From the main road the site is about 1500 meters into the forest and the last 1000 meters you have to walk because it is a closed road. The site can still be a bit tricky to find because the area consists of intersecting forest roads so it can be good to memorize which way you came from. The site itself consists of a memorial and eleven marked mass graves, all surrounded by a fence. When you wander the site you can feel how porous the ground is and easily dug. This was of course an advantage when the mass graves were dug and a contributing factor that the Nazis choosed the site for murder.