A detailed seventeenth-century etching by Reinier Nooms depicting the blockhouses on the Amstel river during a winter freeze.

This etching by Reinier Nooms, often known by his pseudonym Zeeman, captures a winter scene on the Amstel river. The composition focuses on the 'Blokhuizen', or blockhouses, which were defensive structures positioned along the waterway. Nooms, a former sailor, possessed a technical understanding of maritime architecture and rigging that informs the precision of his work. His ability to render the specific details of Dutch vessels and buildings made his prints valuable records of seventeenth-century urban development.

The scene depicts the frozen river as a site of activity. Figures are shown skating, walking, and navigating small sleds across the ice, providing a sense of scale against the imposing blockhouses. The artist employs a clear, linear style, using hatching to define the textures of the stone walls and the frozen surface of the water. The sky remains relatively sparse, allowing the architectural forms and the human activity in the foreground to dominate the visual field.

Nooms was highly regarded for his series of etchings depicting ships and harbour views. His work often appeared in sets, intended for both collectors and those interested in the naval power of the Dutch Republic. This particular print reflects the artist's interest in the intersection of military infrastructure and daily life. The inclusion of a windmill in the background and the various types of boats moored near the structures provides a comprehensive view of the river environment during the period. The etching demonstrates the characteristic clarity of the Dutch Golden Age printmaking tradition, where technical skill was applied to document the changing face of the Netherlands. The work remains a primary source for historians studying the defensive layout of Amsterdam and the surrounding regions during the mid-seventeenth century.