Geographically, the island divides into three areas: The soil and geology of the northern part of the island is made up of sand and gravel deposited during the deglaciation, while the southern part is made of both areas of boulder clay (Danish: moræneler) and outwash plains (Danish: smeltevandsslette).

Here a larger part of the countryside is uncultivated and it presents a wavy landscape of meadows and small patches of woodland and heath.

A group of small islands (Kyholm [da], Lindholm, Rumpen, Vejrø) are located east of Stavns Fjord, in Kattegat.

The South Island is home to the seat of the mayor and Samsø's largest town Tranebjerg, but there are many other hamlets and villages (18 in all) spread across the countryside.

Most of the land on the South Island is cultivated, but there are spots of nature like the forest Brattingsborg Skov [da] and the cliffs, shrubs and beach meadows on the southcoast.

Samsø first became an island approximately 9,000 years ago and there are several traces like dolmens, burial mounds, passage graves, kitchen middens, etc.

This did not stop Arngrim's granddaughter Hervor from approaching the mounds and demanding the enchanted sword Tyrfing from her father Angantyr.

The canal was about 500 m long and 11 m wide and could in its time be navigated by vessels with a draught of up to 1 m. It was dug and clad with wooden linings in the years 726-729 AD; the last part of the Scandinavian Iron Age.

[10] All known sources suggest that the island was the property of the Monarchy throughout medieval times, but it was an age of conflict and insecurity nevertheless, as a total of five fortresses were built on Samsø in the Middle Ages; Vesborg where the lighthouse is nowadays, Gammel Brattingsborg where the town of Tranebjerg is now, Hjortholm on the islet of the same name in the Stavns Fjord lagoon, Bisgård at the bishop's palace (official residence) in the parish of Onsbjerg and the small fortification of Blafferholm in the garden of Brattingsborg manor.

The National Museum of Denmark initiated thorough archaeological investigations of the fortification sites a few years ago and the field work terminated in 2012.

Nowadays, farming is still an important business and the biggest contributor to the islands economy, but compared to the rest of Denmark, it has developed in its own direction.

Free range farming is very prominent, and the agricultural produce comprise mostly potatoes, various other vegetables and berries as well as some animal husbandry.

Close to 16% of the islanders work in the fishing and farming sector, not including derived labour, compared to 3.5% countrywide.

[16] Samsø is popular among French, Welsh and Irish people for strawberry picking during the months of June and July every year.

It comprise farming of a large variety of vegetables, grains and fruits, livestock meat and products (lambs, sheep, yarn, cows, pigs, horses, donkeys, goats, chickens, eggs), a dairy, a brewery, restaurants and cafés, candy production, permaculture and forest garden experiments.

There are several plans for extending the overall ecological production and broaden the industry (a slaughterhouse, orangery, forest gardens and education), with a wish for creating more jobs and opportunity for inhabitants of the island.

In addition to that, 10 offshore turbines (making a total of 21 altogether including land-based windmills), were completed in 2007, funded by the islanders.