LCZ stands for Local Climate Zone. This dataset consists of 500,000 Sentinel-1 and Sentinel-2 image patches of 42 urban agglomerations (plus 10 smaller regions) and their corresponding local climate zones (LCZ) annotations. The dataset was annotated by 15 experts in 6 months in strict accordance with the workflow and evaluation process. This dataset can be used to study the use of machine learning technology to monitor urban growth and respond to climate change.