Close to the Catacombs of San Callisto are the large and impressive Catacombs of Domitilla (named after Saint Domitilla), spread over 15 kilometres of underground caves.
The Domitilla Catacombs are unique in that they are the oldest of Rome's underground burial networks, and the only ones to still contain bones. They are also the best preserved and one of the most extensive of all the catacombs. Included in their passages are a 2nd-century fresco of the Last Supper and other valuable artifacts. There are almost 150,000 bodies buried in the Catacombs of St. Domitilla.
They are the only catacombs that have a subterranean basilica; entrance to the catacombs is achieved through this sunken 4th-century church, at via delle Sette Chiese 282. In the past, the basilica had become unsafe, and was abandoned in the 9th century. It was rediscovered in 1593, and much of it was reconstructed in 1872.References:
Tyniec Benedictine abbey was founded by King Casimir the Restorer probably around 1044. Casimir decided to rebuild the newly established Kingdom of Poland, after a Pagan rebellion and a disastrous Czech raid of Duke Bretislaus I (1039). The Benedictines, invited to Tyniec by the King, were tasked with restoring order as well as cementing the position of the State and the Church. First Tyniec Abbot was Aaron, who became the Bishop of Kraków. Since there is no conclusive evidence to support the foundation date as 1040, some historians claim that the abbey was founded by Casimir the Restorer’ son, King Boleslaw II the Generous.
In the second half of the 11th century, a complex of Romanesque buildings was completed, consisting of a basilica and the abbey. In the 14th century, it was destroyed in Tatar and Czech raids, and in the 15th century it was rebuilt in Gothic style. Further remodelings took place in the 17th and 18th centuries, first in Baroque, then in Rococo style. The abbey was partly destroyed in the Swedish invasion of Poland, and soon afterwards was rebuilt, with a new library. Further destruction took place during the Bar Confederation, when Polish rebels turned the abbey into their fortress.
In 1816, Austrian authorities liquidated the abbey, and in 1821-1826, it was the seat of the Bishop of Tyniec, Grzegorz Tomasz Ziegler. The monks, however, did not return to the abbey until 1939, and in 1947, remodelling of the neglected complex was initiated. In 1968, the Church of St. Peter and Paul was once again named the seat of the abbot. The church itself consists of a Gothic presbytery and a Baroque main nave. Several altars were created by an 18th-century Italian sculptor Francesco Placidi. The church also has a late Baroque pulpit by Franciszek Jozef Mangoldt.