One in a ring of forts - Warsaw

1878-82 - a ring of forts according to designs of General Edward Todtleben (1818-1884) was built; forts marked with numbers and letters of russian alphabet. Work started 1879.

Forts on right bank of river Vistula:

Fort I Mlynkovski
Fort II Mierzwiaczka
Fort III Deblin
Fort IV Borova

and on left bank:

Fort V Borek
Fort VI Glusiec