It's always hard to know just how big an area is until you're standing in it. Whilst it's not the most picturesque square I've been it's Red Square in Moscow, so much history. It can get very crowded and I mean very crowed especially on a warm Sunday. There is a dire lack of public toilets and finding a store that has a facility available to the public is difficult so make sure you go before you go.
If you own or manage Red Square (Krasnaya ploshchad), register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.