Oak Bar is part of Hotel Opera in Gothenburg, occupying the space between two hotels that have since merged into one. Its interior and extensive bar selection are intended to bring tradition and modernity together. The menu includes modern and traditional cocktails, champagne, wine and non-alcoholic drinks.

A visit can centre on the drinks menu. It offers cocktails in both modern and traditional styles, alongside champagne and wine, and includes non-alcoholic beverages. The bar's stated approach links what is served with the interior: both are part of an effort to combine tradition and modernity at Hotel Opera. The menu therefore gives visitors a choice of cocktails, champagne, wine and non-alcoholic beverages, with cocktails offered in two styles.

Oak Bar is certified according to Svensk Miljöbas, a Swedish environmental management standard. The standard sets clear requirements for systematic sustainability work in daily operations. The certification concerns the restaurant's work under that standard.