Slemmestad is a village in Røyken in Asker municipality in Akershus, Norway.
Slemmestad was built around the Aktieselskabet Christiania Portland Cementfabrik cement plant.
This is an ancient, sunken part of the crust reaching in the south at sea level and extending north to Brumunddal in the Ringsaker municipality of Hedmark County.
By subsidence, the Oslo field had preserved a comprehensive sequence of shale, limestone, siltstone and sandstone of the Cambrian period.
It features photographs, artifacts, records and other documentation that shows 100 years of development of cement production and the great importance of the factory was Slemmestad and the people who lived there.