Every foreigner needs a visa to travel to Russia. In order to get it, you need an invitation (visa supporting letter). After that, you can apply for your visa at a Russian Consulate either by yourself or through a local travel agent.

Registration

Foreign citizens staying longer than 1 day in Moscow need to register their stay. Registration can be done upon arrival in the hostel.

St. Basil's Cathedral

Probably the most famous sight in all of Russia.
Commissioned and build by Ivan the Terrible in 1561.