This stop is actually a district within the Pijp. It is known as Diamantbuurt, or the diamond district. From the late 1800s until WWII this area was the hub of Amsterdam's world-class diamond industry.
At the GPS location for POI No. 4 you are standing in front of the former headquarters of the Royal Asscher Diamond Co., which was founded in 1854. At its peak, this factory employed around 300 diamond cutters. It was in this building in 1908 that the Cullinan, the largest crude diamond in the world, was split and cut.
Follow the GPS west on Tolstraat, then take a left onto Diamantstraat and notice the squat houses on either side of the street. These were built in 1891 to house the diamond factory laborers.
Continue to walk down Diamantstraat until you see the round building on the right at the intersection with Smaragdstraat. This building was built in 1926 as a public bathhouse for the neighborhood. In those days, before many houses had built-in bathrooms, these bathhouses were common and built by the city to encourage cleanliness. These public bathhouses were popular community gathering places through the 1950s, when their popularity started to decline. Amsterdam's bathhouses were finally closed in the 1980s.
To learn more about the history of diamonds, and Amsterdam's diamond industry, go to the Diamond Museum in Amsterdam's Museum District at Paulus Potterstraat 8. The museum is open daily 9am-5pm, cost is €7.50 for adults 18-64 and €5 for children 13-18 and seniors. Kids infant to 12 are free.
Continue down Diamantstraat to the canal and turn right onto Jozef Israelskade. Cross the busy Van Woustraat and walk two blocks, turning right onto P.L. Takstraat.