Start: Day minus 1 - Adventure racing involves a huge amount of preparation, of equipment, race food and then an understanding of the course. Here competitors are briefed by race organiser Staffan Bjorklund on the evening before departure. Teams came from nine countries, Sweden, Finland and Estonia, and also from France, Spain and Canada.

Day 1 - at 4pm the race began, with the 23 teams abseiling down a dedicated rope off the Downtown Camper Hotel. Each of the four team members took a turn on the 30 metre descent before gathering for Leg 2 of the race, a 6.5 km orienteering course around the city.

Teams then started a 16km pack-rafting section, which involved each team member reaching checkpoints around the city's many waterways.

The weather was not kind on Day 1 of NIAR 2018. This is important as teams may be wet for much of the course, leading to problems with trench foot and with the cold.

Day 2 of NIAR 2018 proved kinder with the weather as the teams made their way north on a 230km mountain bike leg that took them to the coast and the daunting open-water kayaking leg across to the Aland Islands.

The 84 km swim run leg involves swimming as much as 500 metres from island to island, often in the night. Teams are constantly wet from the water crossings.

Adventure racing continues non-stop. Here a team emerges from the water after a swim through the darkness.

Day 4 of NIAR 2018 - with some relief for their feet - after swimming and running for 85 km - teams loaded into sea kayaks to continue through the Aland islands.

Even after the kayaking, there was plenty of paddling on Day 4 of NIAR 2018. Teams paddled and carried their pack-rafts for another 80km through the last of the islands to mainland Finland.

Day Zero -  On the Sunday morning teams went into ‘lockdown’, with mobiles and laptops forbidden. They received maps and precise details of the course and checkpoints. Navigation is a crucial aspect of adventure racing – races are won and lost on successful route-finding and map reading – and so it is a vital to spend time on it.

The novelty with the orienteering course was that teams were given a copy of a 17th Century map of the city to work from. Bridges have changed – some have appeared, others disappeared apparently – and even the coastline has changed in places as land has been reclaimed.

Pack-rafting uses inflatable rafts which are easy to carry and very versatile. Teams found themselves leaving the city by some of Stockholm's less known waterways.

Teams must be versatile in adventure racing. Here a team transports their mountain bikes across water on their pack-rafts.

The weather looked good for the kayak leg to the Aland Islands, but the sea got up and it had to be closed for safety. Teams were transported to the island of Eckero and released in the order they arrived at the kayak start.

Day 3 of NIAR Good navigation was vital as teams make their way from checkpoint to checkpoint in the forest of the Aland Islands.

And racers have to snatch any moment of sleep they can. Here a competitor takes a moment to recover during the swim-run section

Next they transferred into pack-rafts, which can be deflated and stowed away when needed.  Here a team hikes their rafts across an island to the next launch point.

The Finish Line - After a 90km bike ride and a final 7km on foot, teams made their way to the finish line near Turku in Finland. Winners Team Swedish Armed Forces arrived after 84 hours 35 mins - and here gave the gutteral cry of a Viking victory.