The position and the layout of Stahlberg Castle clearly indicate that it is founded in the 12th century. It is situated on a rocky projection to the northwest of the town. The ring wall, parts of which have been rebuilt, surrounds the whole area and is rectangular in shape with several openings. A prominent circular tower that rises next to the gateway like a keep was added at the start of the 13th century and secures the narrow entrance with its curtain wall and a ditch. This part of the design is based on a similar feature at Stahleck Castle. The original keep can probably be identified in the ruins of an angular tower in the upper part of the castle.
References:The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.