First post on here so hopefully its in the right place! I'm heading off on long term solo trip in mid february from UK, starting with train across Europe then into Russia mid in february, have booked trans-mongolian railway to Beijing departing Moscow on 28th February, im not travelling with a lavish budget (i know big cities wont be cheap!) and would like to see Moscow sights and St Petersburg sights prior to train departure, i'm really after any do/ don't do advice or any must see places, im interested to experience local customs and culture and luckily i dont mind the cold ;)
Well, that's a really broad question. I can offer some advice, but not sure if it's exactly what you're looking for. I'd recommend doing some searches on this forum, Googling 'things to do in ...', or just flipping through some guidebooks at your local bookstore, over some coffee maybe.
St. P's "don't miss", though Peterburg is definitely worth a few days. Beautiful in the snow, unless you're trying to walk on it...
- Hermitage. Free one day of the month, go check out their website to see which day. I think it's first Thursday but not sure. It's a fantastic museum in a beautiful building.
- Dostoevsky House Museum
- Nevskiy Prospekt. Lots of sights on this street.
Moscow: I spent around a month here and haven't seen it all, so just get lost...
- Red Square & surroundings (St. Basil's, Kremlin, etc), obviously.
- Arbat walking street
Customs & tips:
- Russians come across as rude sometimes, but not if you get to know them. You can find local place pages / discussions on Couchsurfing and arrange to meet up with some people that way. If you're in open carriage, or even kupe on the trans-siberian, you'll have a chance to meet people.
- bring your own teabags and just-add-hot-water dinners on the train with you. And alcohol if you're into it; maybe you'll make some friends that way.
If you want other advice, please feel free to post some more specific questions!

Hi
How much time do you have for sightseeing of Moscow ?
By the way about local customs and culture . In Russia will be ancient slavic holiday "Maslenitsa" from 16 to 25 February .
Thank you for replies, I plan to spend around a week in Moscow and train to St Petersburg and spend 2-4days there before leaving on train. Also I'm stopping at Urkutsk in Siberia for 2/3 days on the way so any suggestions for there appreciated too!!
Thank you for replies, I plan to spend around a week in Moscow and train to St Petersburg and spend 2-4days there before leaving on train. Also I'm stopping at Urkutsk in Siberia for 2/3 days on the way so any suggestions for there appreciated too!!

If you haven’t bought the ticket yet, I think would be better spend more days in St. Peterburg.
It was the capital of the Russian Empire during the period of greatest power and there a lot of beautiful places and buildings.
About Moscow
Places were grouped near each other . On top of the list are the most important places to visit
St. Basil's Cathedral
Red Square (Krasnaya ploshchad)
Alexander Garden (Aleksandrovsky Sad)
Tomb of Unknown Soldier
Diamond Fund (Almazny Fond)
The Armoury
Moscow Metro
State Historical Museum
Foreign Affairs Ministry
Old Arbat (Stary Arbat)
House of friendship with peoples of foreign countries (A.A. Morozov's mansion)
Christ The Savior Cathedral
Pushkin State Museum of Fine Arts
Luzhkov Bridge
Tretyakov Gallery in Lavrushinsky Lane
Muzeon Museum
Crimean Bridge (Krymsky Most)
Pushkin Square
Tverskaya Street (Ulitsa)
Bolshoi Theatre
Lubyanka square
Trinity Temple in Nikitniki
Kitai-Gorod and Ulitsa Varvarka
Chambers of The Romanov Boyars
Old English Court
Victory park
Central Museum of the Great Patriotic War of 1941-1945
Triumphal Arch
Borodino Battle Museum Panorama
Kolomenskoye Historical and Architectural Museum and Reserve
Palace of Tsar Alexei Mikhailovich in Kolomenskoye
Tsarytsino Open-Air History and Architectural Museum
Worker and Collective Farmer Museum and Exhibition Center
Ostankino TV Tower
Museum of Astronautics
Izmailovsky Park
The Vodka Museum
Souvenir market
Lomonosov Moscow State University (MGU)
Sparrow Hills (Vorobyovy Gory)
Novodevichy (New Maiden) Convent and Cemetery
Moscow Compound of the Holy Trinity and St. Sergius Lavra (70 km away from Moscow)
Central Andrei Rublev Museum of Early Russian Art
Central Armed Forces Museum of Russian Federation
Cold War Museum at the Bunker-42 on Taganka
Sokolniki Park
Ice Museum
The Museum of Russian Icon