King Carol II and Lake's Sluice
The Herastrau Lake was arranged between 1930 - 1935 through draining of a swamp located at that time at the edge of the town.
Herăstrău Lake Sluice was built between 1933-1936 replacing an old dam, which served a mill.
Initial sluice project belongs to Dorin Pavel engineer. Besides boat trips from one lake to the other and flood draining purpose, another purpose of the project was to serve as a reduced scale model for future locks along channel Bucharest-Oltenita.
Inauguration of the sluice and dam was made during "Bucharest's Month". King Carol II of Romania in person was on the first boat that passed through the lock.
Once Herăstrău Sluice was opened in 1940, it has worked for a short time for leisure walks with small boats. Not maintained over time, the sluice function has been abandoned, being converted into extra surge periods waters.

Lock rehabilitated
After 70 years from construction, 50 years of downtime and more than one year of renovations, the sluice was restored to the original shape and appearance. It was put into operation in September 2007.
According to Virgil Carstea, although Herastrau Sluice is ten times smaller than Iron Gates one on the Danube, is equally complex.

The easiest access to the cache is from Nordului Avenue, see the waypoint.
Source: wiki