The most interesting part of the Customs Museum is its section on smuggling. The oldest exhibits date from the 1920s and 1930s when alcohol was smuggled in from Estonia and Finland. One of the oldest pieces is a pair of XXL knickers dating from the 1920s, with secret pockets to conceal cannisters filled with 96% proof spirit, home-made by a lady caught by Swedish customs (a gurgling noise was heard by customs officers). Other methods for concealing contraband included bread, sofas and teddy bears. In 1622 a fence and toll (tull) booths were built around Stockholm to raise money for the wars of King Gustav II Adolf, and the museum displays a copy of one of these, as well as an early 20th-century customs office. Though it's a bit off the beaten track, the Customs Museum is free, so take a peek if you're in the area.