The oldest traces of wood and earth fortifications on Wawel Hill date back to the 9th century and have been preserved in archaeological layers, while remnants of stone walls from the 13th century and brick Gothic walls from the 14th–15th that defended the hill until the end of the 18th century have survived to this day. In the 16th–17th centuries, the walls and earth fortifications, which had deteriorated to the point of nearly disappearing, were restored, while the fortifications from the years 1790–1792, which were used by the Austrians in the years 1849–1854 during the construction of the outer perimeter of the citadel, have been preserved. The Austrians occupied Wawel in 1846, and in 1850 the fortifications of the Krakow Fortress began to be erected on the hill. Attention is drawn to two basteje-caponiers, from Straszewskiego Street and almost unchanged under the Kurza Stopka (Hen Foot). The fortifications from the times of Augustus the Strong were also upgraded. The eastern and southern sections of the walls assumed their present form in the mid-19th century, whereas the remaining ring walls were transformed during conservation works in the 20th century. The fortress gates at Kurza Stopka and Lubranka have retained their 19th century shape. Three new gates were built, and the gate of the Stronghold in Sandomierz was rebuilt. Most tourists are not aware that the walls they pass while climbing the hill, first of all the Stronghold of Wladyslaw IV with the Tadeusz Kosciuszko Monument, are not medieval fortifications but modern ones with powerful oval caponiers. The fortified hill, occupied by the imperial army as barracks, became the central point of the Krakow Fort – a citadel fortress.