Three of Moscow's mainline railway stations, which welcome trains including most services from St. Petersburg, Trans-Siberian services from Beijing and Vladivostok, and international services from Central Asia, Tallinn, and Helsinki, are located on Komsomolskaya Ploshchad, roughly 4km to the north-east of the Assambleya Nikitskaya Hotel.
By taxi
Cabs from the three stations should take around 20 minutes to reach the Assambleya Nikitskaya Hotel. If you are prepared to negotiate a cab on arrival, you should try not to pay much more than $20, but it is probably easier to arrange a transfer with a driver to meet your train, which you can do here.
By metro
From Komsomolskaya Metro Station, accessed from all three mainline stations, travel south-west on the red line four stops south to Okhotny Ryad, which is less than ten minutes' walk from the Assambleya Nikitskaya Hotel.
