St. Lambert's Church is the main Evangelical Lutheran church in Oldenburg. It dates back to the 13th century and was renovated in the 19th century. The church was initially built as a Roman hall in 1155, and was later converted into the city's cathedral. The church has a stunning interior design inspired by the design of the Pantheon in Rome. The church also houses a valuable collection of paintings and statues that adorn it from the inside.