One of only two remaining wooden buildings in central Amsterdam, dating from around 1550. It sits on the Zeedijk, the old sailors' quarter, and has been a bar for most of its existence. The interior is dark, cramped, and full of character — low ceilings, creaking floors, and the unmistakable sense of a building that has seen five centuries of drinking.
A proper brown café (bruine kroeg) in every sense. No cocktails, no pretension, just beer and jenever in a building that was old when Rembrandt was young. The Zeedijk was rough for decades but has gentrified considerably — In 't Aepjen is a survivor from a wilder era.