Moscow Metro is very huge and there are 11-12 different lines. I think the biggest problem is the letters. Nothing is in Latin alphabet. Thanks to my husband WHO can ready russian. this way we never used taxi in Moscow but only metro. Each station is unique and like an art gallery with mosaics and chandeliers. the only problem for us was that there is no elevator or escalator in most of the stations and this made our job so hard with a stroller.