The Mews was a highlight of our London visit, in part because it was so easy to see! Just a short walk from the Palace (good to do the two together), there was no line to enter and no real crowd (later that same day we were with hundreds of other people entering the Palace). There is a great audio tour which explains the history and significance of each of the carriages and shows times when each carriage was used for official royal purposes. One walks through the horse stables (we saw just one) and sees the courtyard area around the stables and the residences of the keepers. It doesn't take long, so plan about 30-45 minutes. There's a small gift shop at the end. If it is hot, take a bottle of water as it is quite sunny and hot. Happily, this was the only place in all of London that I encountered a water vending machine (as of Aug '22)!