During Pentecost 1976 one of the most important Swiss murder cases happened: near the weekend house "Waldeggli", five were killed brutally.

The Seewen murder case counts as one of the biggest unsolved crimes in Swiss criminal history.

[4] Seewen has an area, as of 2009[update], of 16.3 square kilometers (6.3 sq mi).

Of the rest of the land, 0.95 km2 (0.37 sq mi) or 5.8% is settled (buildings or roads), 0.06 km2 (15 acres) or 0.4% is either rivers or lakes.

It consists of the village of Seewen and the settlements of Steinegg, Moos, Unterackert and Rechtenberg.

The blazon of the municipal coat of arms is Per fess wavy Gules a Mullet Argent between four, two and two, Reed Panicles proper and of the second a Fish Azure naiant.

[8] The age distribution, as of 2000[update], in Seewen is; 88 children or 9.2% of the population are between 0 and 6 years old and 155 teenagers or 16.2% are between 7 and 19.

[9] The historical population is given in the following chart:[3][14] The Museum für Musikautomaten, a museum of music automatons such as player pianos, mechanical organs and other self-playing music instruments, is listed as a Swiss heritage site of national significance.

It is a Swiss federal museum and has one of the world's largest collections of its kind.

[15] Among its exhibits is a Welte Philharmonic Organ built for the HMHS Britannic but not installed on the ship due to the outbreak of the First World War.

[16] The entire village of Seewen is part of the Inventory of Swiss Heritage Sites.

[17] In the 2007 federal election the most popular party was the SVP which received 30.45% of the vote.

[9] There were 501 residents of the municipality who were employed in some capacity, of which females made up 41.5% of the workforce.

The number of jobs in the primary sector was 43, of which 38 were in agriculture and 5 were in forestry or lumber production.

In the tertiary sector; 7 or 17.5% were in wholesale or retail sales or the repair of motor vehicles, 5 or 12.5% were in the movement and storage of goods, 5 or 12.5% were in a hotel or restaurant, 4 or 10.0% were technical professionals or scientists, 5 or 12.5% were in education.

[9] From the 2000 census[update], 564 or 58.9% were Roman Catholic, while 195 or 20.4% belonged to the Swiss Reformed Church.

The education system in the Canton of Solothurn allows young children to attend two years of non-obligatory Kindergarten.

All the lower secondary students from Seewen attend their school in a neighboring municipality.