[2] In 1939, he completed three large paintings to be hung in the new state high school at Struer.

One of the paintings shows the town of Struer and its harbour, the two others present scenes from Klovvig on the island of Venø.

After the war, Agger frequently returned to his summerhouse on Venø where he worked on numerous landscapes and sketches until heart problems put an end to his journeys there in 1965.

In his later years, he focused increasingly on using stones he had found on Venø as a basis for his skies.

Knud Agger's final work was an 8m tall stained glass window at Abildgård's Church in Frederikshavn.