Despite the ongoing war, the Northern Karelia Cooperative Society had 5-storey facilities built at the corner of the Siltakatu and Torikatu streets in 1942. The building was designed by architect Paavo Riihimäki in 1939. The facilities were first in military use, and Hotel Pohjois-Karjala with 36 guest rooms opened in June 1943. The name of the PK Restaurant, located on the second floor, was quickly twisted into "Pekka Kettunen" in the mouths of the local inhabitants, a name still remembered by the senior clientele.

During the war, Pekka Kettunen was a soldier's paradise, fondly remembered by veterans. It was a place to relax and forget the horrors of the war for a little moment on the way home or back to the front. Officers used to dine at the restaurant and could even drink alcoholic beverages there – and they certainly made the best of this very important benefit.

In 1982, SOK acquired the hotel and included it in the Sokos Hotel chain of the S Group. The name was changed to Sokos Hotel Vaakuna. In 2002, the cooperative purchased Vaakuna back. An extension to the hotel was completed in 2010, doubling the number of guest rooms and renewing the restaurant concept. The hotel has now 144 rooms.