Pentre Ifan contains and gives its name to the largest and best preserved neolithic dolmen in Wales. As it now stands, the Pentre Ifan Dolmen is a collection of seven principal stones. The largest is the huge capstone, 5 m long, 2.4 m wide and 0.9 m thick. It is estimated to weigh 16 tonnes and rests on the tips of three other stones, some 2.5 m off the ground. There are six upright stones, three of which support the capstone. Of the remaining three, two portal stones form an entrance and the third, at an angle, appears to block the doorway.
The dolmen dates from around 3500 BC, and has traditionally been identified as a communal burial. Under this theory the existing stones formed the portal and main chamber of the tomb, which would originally have been covered by a large mound of stones about 30 m long and 17 m wide. Some of the kerbstones, marking the edge of the mound, have been identified during excavations. The stone chamber was at the southern end of the long mound, which stretched off to the north. Very little of the material that formed the mound remains. Some of the stones have been scattered, but at least seven are in their original position. An elaborate entrance façade surrounding the portal, which may have been a later addition, was built with carefully constructed dry stone walling. Individual burials are thought to have been made within the stone chamber, which would be re-used many times. No traces of bones were found in the tomb, raising the possibility that they were subsequently transferred elsewhere.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.