not so long ago, the new Moscow Central Circle train line opened (Московское центральное кольцо, МЦК).
The line has a length of 54 kilometres and currently 26 stations are open with 5 more opening soon.
The ticket system is fully integrated with the Moscow metro, so you only need one ticket, also if you want to connect to this new train service.
Some stations, such as Ploshad Gagarina, are directly connected to the metro stations, others have the stations within walking distance (here you will also be charged only for one ride).
During the first month (until 10th of october), the use of the MCC is free of charge, so anybody who wants to try out the train can do so without paying.
I did some days ago and was pleasantly surprised. I did not have time to do the full circle but I rode the half and the train is very pleasant. It is a new built Siemens train and very comfortable. Only pity is that they did not put power ports at every seat. These are only available in the front seats close to doors.
I add you here also the map of the Moscow metro (including expansion plans), so you can understand better, where the new line is situated.
(By Sameboat – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=24461295)
Interesting for tourists to note is, that this line stops and passes by exactly Moscow city, the new business district as well as the botanical garden.