This heat balloon fest is a top Sergiev Posad event and a major nationwide professional contest. Happening outside the Lavra on Sergius' nameday (July 18) and the weekend ahead, it features about 10 colorful airships of incredible shapes. Beside a traditional moneybag, the fest's highlight is the Matryoshka balloon. At night the balloons even become illuminated.
I advise timing your Sergiev Posad visit to St. Sergius Sky to watch this magnificent annual sight.