This is an original antique map titled “Karstia, Carniola, Histria et Windorum Marchia,” published by Willem Blaeu in Amsterdam circa 1640. The map depicts the historical regions of Karst (Karstia), Carniola (modern-day Slovenia), Istria (the peninsula shared by Croatia, Slovenia, and Italy), and the Windic March, a medieval border territory. The engraving shows detailed place names, rivers, mountains, and settlements across present-day Slovenia, northeastern Italy, and northwestern Croatia. The Gulf of Trieste is prominently illustrated at the lower left, with Trieste labelled and coastal settlements clearly indicated. The Adriatic Sea is elegantly engraved with stippled waters, a compass rose, rhumb lines, and a sailing ship, enhancing its decorative maritime appeal. In the upper left corner is a beautifully designed cartouche bearing the title within a scrollwork frame with foliage and drapery motifs. The lower left includes a mileage scale in Italian miles and a dedication to Guiljelmus Blaeu excudit, confirming its publication from the Blaeu workshop. Condition: Good condition. Strong, clean impression on laid paper with wide margins. Light age toning and faint foxing in blank margins, minor creasing along the original centre fold as issued. No tears or repairs noted. Fully suitable for framing.