This is a small museum (MOP5) right next to the famous and important Lin Fong Temple on Ave. do Almirante Lacerda. It is dedicated to important early 19th-century Mandarin Commissioner Lin Zexu.
Here you find a large outdoor statue of Commissioner Lin Zexu. Within the museum, you will learn the history of Zexu's visits to Macau and his dealings with Western powers such as the Portuguese and British in relation to opium trading in China, which eventually escalated into the infamous Opium Wars.
You can visit the museum from 9am to 5pm daily (closed Mondays). It is small and can be conveniently visited in 10-20 minutes before or after spending time in the Lin Fong Temple. Those with stronger interest in historical China-West relations and the Opium Wars may want to spend a bit more time here going through the various text displays.