Helga Trefaldighet (Holy Trinity) Church was inaugurated in 1302. It replaced the previous church of local Ullerås parish. The church is made of grey stone and brick and it was originally a three-nave basilica. The western tower was added in the 15th century. The church was damaged badly by fire in 1702.
The interior is particularly notable. It is decorated with paintings by the famous medieval artist Albertus Pictor, which were created in the second half of the 15th century. Of particular interest is the depiction of The Visitation, regarded as one of the finest surviving medieval paintings in Sweden.
Kerameikos was the potters" quarter of the city, from which the English word 'ceramic' is derived, and was also the site of an important cemetery and numerous funerary sculptures erected along the road out of the city towards Eleusis.
The earliest tombs at the Kerameikos date from the Early Bronze Age (2700-2000 BC), and the cemetery appears to have continuously expanded from the sub-Mycenaean period (1100-1000 BC). In the Geometric (1000-700 BC) and Archaic periods (700-480 BC) the number of tombs increased; they were arranged inside tumuli or marked by funerary monuments. The cemetery was used incessantly from the Hellenistic period until the Early Christian period (338 BC until approximately the sixth century AD).
The most important Athenian vases come from the tombs of the Kerameikos. Among them is the famous “Dipylon Oinochoe”, which bears the earliest inscription written in the Greek alphabet (second half of the eighth century BC). The site"s small museum houses the finds from the Kerameikos excavations.