Among the numerous objects of defensive architecture, attention should be paid to e.g.: barracks building erected in 1864-75, having 2300 m in length, built on an irregular polygon plan. With a large inner courtyard, Napoleon's redoubt built in 1811-12 as an intersection in the form of a cannon station, brick, two-story, arranged on a square plan with an internal courtyard, surrounded by a moat, and cannon station of gen. Dahna built in 1839 r. as a cover for the bastion of the inner perimeter of the fortress, brick, two-story, having 52 artillery positions, arranged on a semicircle plan with 2 single-story wings and an internal courtyard, surrounded by a moat and against a slope. Officers' casino From the third quarter of the 19th century., currently the Garrison Club. Brick and plastered building, from the outside in the neo-gothic style. Inside, there are white marble stairs and a wrought-iron balustrade, decorated with floral ornaments and two griffins on the sides. The architecture of other buildings is also interesting, such as gates, water tower, mill, bakery, powder magazines, racing pigeon station, power station, and even latrines. Some objects of the fortress not used at present, np. kazamaty, shelters and shelters, they are a convenient habitat for bats. Part of the forts, np. in Janówek or Dębina, it is used for training people practicing mountain climbing.

Monument to the Defenders of Modlin in 1939 r., unveiled in 1957 r., in the form of a granite pillar topped with a candle. On the sides 2 Soldiers characters and 2 cannons. Before World War II, a bust of Józef Piłsudski was placed on the plinth instead of a candle.

At the fortress cemetery, founded in 2 half. XIX w. for the needs of the Russian fortress crew (in the north. -zach. parts of the fortress between the outer perimeter of the fortifications and the road), orthodox cross, the grave of German soldiers who died in 1915 r., graves of Polish legionnaires who died in the years 1918-20, graves approx. 500 Polish soldiers who died in 1920 r., graves of Polish soldiers who died in September 1939 r. and unveiled in 1997 r. Monument to the Polish soldiers who died in 1920 i 1939 r.