Keturiasdesimt Totoriu (town of the 40 Tartars) is located just outside Vilnius city, but within the district of Vilnius, Lithuania.
One of ,if not the first settlement of Tartars (Muslims or Turkic origin) in Lithuania, this mosque, in the design of the original though renovated in recent generations, celebrated it's 610 year anniversary this year.
The Tartars were invited to Lithuania by Grand Duke Vytautas (d.1430).
The town is located in the black forest in one of the suburbs of Vilnius, the capital city. There are also 4 Muslim graveyards, one of which is located in a 4 acre plot of land with gravestones going back nearly 600 years, though, the small stones seen alongside this mosque are also gravestones, the oldest I found dated back to 1807.