![Photo taken on June 3, 2019 shows the Kazan Cathedral in St. Petersburg, Russia. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/386470dcb2a3445cb40e9a9be20d2c71.jpg)
Photo taken on June 3, 2019 shows the Kazan Cathedral in St. Petersburg, Russia. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Photo taken on June 4, 2019 shows buildings by the Neva river in St. Petersburg, Russia. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/6f6f199f13a14df5824c96746a10206b.jpg)
Photo taken on June 4, 2019 shows buildings by the Neva river in St. Petersburg, Russia. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Photo taken on June 3, 2019 shows the Neva river in St. Petersburg, Russia. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/32ec35a7d5614dc8b5e91abb2ce22cd0.jpg)
Photo taken on June 3, 2019 shows the Neva river in St. Petersburg, Russia. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Tourists pose for pictures at Dvortsovaya Square in St. Petersburg, Russia, June 4, 2019. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/dde494ae25cd41a1a4703e6dd976b232.jpg)
Tourists pose for pictures at Dvortsovaya Square in St. Petersburg, Russia, June 4, 2019. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Tourists enjoy themselves at Dvortsovaya Square in St. Petersburg, Russia, June 4, 2019. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/101feb12622b4d2aab410647e11570d9.jpg)
Tourists enjoy themselves at Dvortsovaya Square in St. Petersburg, Russia, June 4, 2019. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Tourists line up to visit the State Hermitage Museum in St. Petersburg, Russia, June 4, 2019. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/6a478ebe302e4c6a8e6fccb49814d807.jpg)
Tourists line up to visit the State Hermitage Museum in St. Petersburg, Russia, June 4, 2019. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Photo taken on June 4, 2019 shows the Cruiser \](http://www.ecns.cn/hd/2019/06/06/adba351243f84c54932e7489f5bd2f0f.jpg)
Photo taken on June 4, 2019 shows the Cruiser "Aurora" in St. Petersburg, Russia. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Photo taken on June 3, 2019 shows Saint Petersburg Stadium in St. Petersburg, Russia. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/0dae713673bd4c3cb4480bf5fe91c0b0.jpg)
Photo taken on June 3, 2019 shows Saint Petersburg Stadium in St. Petersburg, Russia. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Photo taken on June 4, 2019 shows the Peter and Paul cathedral in St. Petersburg, Russia. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/f0eed69ba47247f9828abf9bf2b78c3e.jpg)
Photo taken on June 4, 2019 shows the Peter and Paul cathedral in St. Petersburg, Russia. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![Photo taken on June 4, 2019 shows the Admiralty building in St. Petersburg, Russia. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/ae57984ae4f04fd4b346c58c6b735e81.jpg)
Photo taken on June 4, 2019 shows the Admiralty building in St. Petersburg, Russia. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)
![People run by the Neva river in St. Petersburg, Russia, June 3, 2019. St. Petersburg is Russia\'s second largest city. (Xinhua/Sadat)](http://www.ecns.cn/hd/2019/06/06/a85e132636c3469c97ed2809a4d92848.jpg)
People run by the Neva river in St. Petersburg, Russia, June 3, 2019. St. Petersburg is Russia's second largest city. (Xinhua/Sadat)