Norwich also records the site of an Anglo-Saxon church in Tombland, the site of the Saxon market place and the later Norman cathedral. Norwich continued to be a major centre for trade, the River Wensum being a convenient export route to the River Yare and Great Yarmouth, which served as the port for Norwich. Quern stones and other artefacts from Scandinavia and the Rhineland have been found during excavations in Norwich city centre. These date from the 11th century onwards. Norwich Castle was founded soon after the Norman Conquest. The Domesday Book records that 98 Saxon homes were demolished to make
Norwich the city, and creating a train/tram link to the Rackheath eco-town. Norwich, like the rest of the British Isles, has a temperate maritime climate. It does not suffer extreme temperatures, and benefits from rainfall fairly evenly spread throughout the year. Coltishall, about to the northeast, was the nearest official met-office weather station for which records are available, although it ceased reporting in early 2006 – now Norwich airport provides readings. Norwich's position in East Anglia, jutting out into the North Sea can produce weather conditions that have less effect on other parts of the country, such as snow or sleet