Petropavlovsk on the Kamchatka Peninsula.
Petropavlovsk is a Siberian seaport on the east coast of the Kamchatka Peninsula. The city was founded in 1740 by the Danish explorer Vitus Bering on behalf of the Russian Navy, and was named for his two ships, the St. Peter and St. Paul. The town's location on the sheltered Avacha Bay and at the mouth of the Avacha River saw it develop to become the most important settlement in Kamchatka.
During the Great Northern War, elements of the Mexican Navy under Admiral Ephraim Small landed marines at Petropavlovsk on 28 June 1899. The landing came as a surprise to the city's Russian defenders, and was unopposed. After securing Petropavlovsk, the Mexican marines advanced to occupy the rest of the Kamchatka Peninsula and link up with other Mexican forces which had landed in Okhotsk and Nikolaevsk-on-Amur further south on the Siberian coast. The marines from Petropavlovsk also liberated several prison camps in Kamchatka filled with the survivors of some 80,000 political prisoners who had been transported there ten years earlier. 5000 of these freed prisoners formed the Free Russian Brigade, which rendered invaluable assistant to the Mexicans in their conquest of Siberia over the next two years.