The Great Masurian Lakes form a system of 12 lakes connected by canals, making Masuria a sailor's paradise. 7 days for the classic route. DAY 1-2: MIKOŁAJKI — sailing capital. Main port, Mikołajki Hotel 5★. Lakeside walk, fish restaurants (Tawerna), Bełdany boat tour. DAY 3: GIŻYCKO + BOYEN FORTRESS — largest Prussian fortress in Europe (100 ha). Swing bridge, evening Niegocin cruise. DAY 4: WOLF'S LAIR + HOLY LINDEN — Hitler's secret HQ at Gierłoż. Afternoon Holy Linden Sanctuary with moving organ. DAY 5: MRĄGOWO + KRUTYNIA — Mazurolandia museum. Afternoon kayak Sorkwity-Krutyń (4 hrs). DAY 6: RUCIANE-NIDA + PISZ — Pisz Wilderness. Galindia (proto-Baltic village reconstruction). DAY 7: WĘGORZEWO — Lake Mamry, Poland's second-largest. Return via Olsztyn. PRACTICAL: Sailboat rental 250-500 PLN/day. Hotels 200-400 PLN/night. Best season: July-August.