Tretyakov’s Art Gallery. This art gallery is named after Pavel Tretyakov (1832-1898) who had collected about 2,000 works of Russian art and donated them all to the city of Moscow, together with his own house that still holds a part of the exhibition today. Tretyakov’s donation was the basis of what is now one of the largest collections of Russian fine art in the world – more than 130,000 works of painting, sculpture, and graphics.
The Kremlin. I am listing the Kremlin last because everyone knows about it, and if you travel to Moscow you will probably visit the Kremlin anyway. If you do, I recommend that you go to the Armory and Almazny Fond (Diamond Fund). I think those two are the best of the Kremlin museums.
I hope you will find this guide helpful. Have a pleasant trip!