Complex sentence: The city is maybe most famous because of the Nebra skydisk, which was found near the city in 1999, but it only became public in 2002 when the finders tried to sell it and were arrested.
Split into simpler sentences: The city is perhaps most famous due to the Nebra skydisk, which was found near the city in 1999. It only became public in 2002 when the finders tried to sell it and were arrested.