Complex sentence: GeoPlace the organisation that maintains the National Land and Property Gazetteer (NLPG) and the National Street Gazetteer (NSG), which are created and maintained with input from all local authorities in England and Wales.
Split into simpler sentences: GeoPlace the organisation that maintains the National Land and Property Gazetteer (NLPG) and the National Street Gazetteer (NSG). These national databases are created and maintained with input from all local authorities in England and Wales.