Twenty minutes west on the DSB regional train and you are at the edge of the Roskilde Fjord, looking at the town that was Denmark's capital for three centuries before Copenhagen assumed the role. Roskilde station is at the top of the hill; the harbour and the Viking Ship Museum are at the bottom.
Getting There
DSB regional train from Copenhagen Central to Roskilde: 20 minutes. Trains run several times per hour. The fare is approximately DKK 80/€11 single, covered by a Copenhagen travel card. Roskilde station is at the top of the hill, with the harbour and Viking Ship Museum a 15-minute flat walk downhill.
The Viking Ship Museum
The Vikingeskibsmuseet on the harbour (entry approximately DKK 155/€21) is the reason to come to Roskilde. Five Viking ships - scuttled deliberately in the fjord around 1070 AD to block an enemy sea approach, discovered in 1957, and excavated between 1962 and 1969 - are displayed in the main hall in their excavated state. The largest, Skuldelev 2, is a 30-metre longship whose oak timbers have been dated to Dublin, Ireland, around 1042. This is not a replica: it is the actual ship, fragmented and supported by steel framework.
The adjacent boat yard is where craftspeople build full-scale replicas using traditional methods - iron tools, clinker construction, wooden pegs. In May the yard is active. If weather permits, the replicas may be in the fjord. The museum operates seasonal voyages on replica vessels for visitors in May and summer; check vikingeskibsmuseet.dk for departures.
Roskilde Cathedral
The Roskilde Domkirke (UNESCO World Heritage Site, entry approximately DKK 80/€11) is reached by a short walk uphill from the harbour - a 10-minute climb through the town centre. Worth the gradient. The cathedral is the burial place of 39 Danish monarchs from Harald Bluetooth (died 986) to the present dynasty; the accumulation of royal chapels built around the original Romanesque and Gothic nave over five centuries gives the interior a quality found nowhere else in Scandinavia.
For post-marathon legs: visit the harbour and museum in the morning, lunch at the harbour, then the cathedral in the afternoon after the physiological interlude of food.
Where to Eat
Restaurant Snekken on the harbour front, adjacent to the Viking Ship Museum, serves traditional Danish smørrebrød - open rye-bread sandwiches: sild (pickled herring), roastbeef (with crispy fried onions and pickled cucumber), rejer (North Sea shrimps with dill). The setting is directly at the water's edge. Pair with a glass of Roskilde Bryghus ale.
The specific May pastry: hindbaersnitte (raspberry slice) from the local bakeries on the Standertorvet town square.
Getting Back
DSB regional trains from Roskilde to Copenhagen Central run several times per hour, 20 minutes. From Copenhagen Central, Metro Line M2 reaches Copenhagen Airport (Kastrup) in 15 minutes.