After 1830, the new town was established outside the fortress walls and was given the auspicious name "Pylos." The fortress was subsequently abandoned, and the citadel was converted into a prison. Niokastro, or New Navarino, as it was named in contrast to Old Navarino, was built during a period when artillery had become the principal means of both offensive and defensive warfare. Its walls were thick enough to withstand cannon fire, low in height to reduce their exposure to enemy artillery, and sloping to lessen the impact of projectiles. They were further reinforced by powerful bastions. The two most important bastions are located on the seaward side of the fortress—the so-called Seventh Bastion and Santa Maria Bastion—which protected both the entrance to the bay and the harbour. At the highest and most vulnerable point of the fortress, the citadel was constructed. It was further protected by a dry moat, six pentagonal bastions, and nearly sixty cannons mounted along its ramparts. Particularly impressive is the fortress's southern defensive wall, known as the Great Verge (Megali Verga), which connects the citadel with the Seventh Bastion. Access to the fortress was through the imposing southeastern gate, known as the "Zematistra." Today, only the ruins of the houses and public buildings remain within the fortress, together with the imposing mosque, which, following the liberation of Greece, was converted into the Orthodox Church of the Transfiguration of the Saviour.