Denmark is one of the most straightforward countries in Europe for international civil marriage. Fewer documents are typically required than in many jurisdictions, processing is measured in working days rather than months, and the result is a full legal marriage. Within the EU it is recognised by treaty; to use your certificate elsewhere, an apostille and translation may be needed, depending on the country where you present it.
No long residency requirement, no banns or church notices, no in-person interview before the wedding day. For couples with different nationalities, Denmark removes the bureaucratic friction that often makes marrying at home impractical.