In the land-use plan ratified in 1917, the southernmost point of Kotkansaari Island was designated as a park area. Already then, this area was a popular recreation destination. In the 1930s, an oil terminal was set up there despite vehement opposition from the town's population. Access to the oil terminal site by outsiders was prohibited. The oil terminal was closed down in 2002. The site of the oil terminal was thoroughly cleaned up and landscaping was commenced in 2004. The jetties and a few concrete foundations of the oil tanks remain at Katariinanniemi as mementos of the oil terminal days.
This southern point of the Kotkansaari Island has been developed into a park and recreation area 20 ha in size with a wide range of facilities for outdoor activities for the entire family. Magnificent views of the sea, Suursaari Island (part of Russia) in the horizon, and stately rocky outcrops attract visitors to the area the year round.
Playground and fitness equipment are available for people of all ages. Wide expanses of lawn areas make this a wonderful place for playing games and for relaxing. There are numerous spots to stop over at and unique items to see, among them a meditation labyrinth constructed according to an age-old model. Sea water flows from Kalliolampi pond along a brook passing through what has been given the name of "Secret Garden".
The several picnic spots in the area are equipped with barbeques and tables made of granite. Users need to bring along their own firewood or charcoal. The large stone table is composed of seven granite types. As many as 50 people can sit at this table at the one time.
The highest point in this area is occupied by the main fortress, Fort Katariina, dating back to the Ruotsinsalmi fortress town. The construction of this fortress was ordered by Catherine the Great of Russia in the aftermath of the crushing defeat of the Swedish forces at the Ruotsinsalmi sea battle in 1790; Finland was part of Sweden at the time. The purpose of the new fortress was to safeguard the Russian border and especially to protect St. Petersburg. Fort Katariina and the Patteri Katariina (battery) have been restored by Museovirasto (Finland's National Board of Antiquities).
Katariina's Black Alder Grove is a prime example of Kotka's original natural environment, of which little remains on Kotkansaari Island. The grove covers a wetland area rich in birdlife, and it was declared a conservation area in 1964.
A path leads from Katariina Seaside Park via Mansikkalahti and Meriniemi to the Sapokka Water Garden (distance of 1.6 km).