Sadhu Sanga festival by the Black Sea in Russia (Album of photos)
There were about 5000 devotees there!
Srila Prabhupada: The performance of sankirtana-yajna is a special concession for human society to save people from being affected by known or unknown sinful activities. We are surrounded by unlimited sins, and therefore it is compulsory that one take to Krishna consciousness and chant the Hare Krishna maha-mantra. (Srimad-Bhagavatam, 9.16.23 Purport)
Find them here: https://goo.gl/hS9Ea9