AMSTERDAM, Netherlands, Nov. 28 (UPI) -- The Netherlands and Belgium signed a formal treaty Monday for a peaceful land exchange involving the Meuse River.
The signing occurred during a three-day visit to the Netherlands by Belgium's King Filip and Queen Mathilde.
The Netherlands will grow by 24.7 acres in the nations' the first land swap in 175 years.
"You do not see so often that changing borders without firing a shot, but there was an excellent collaboration," Netherland's Limburg Gov. Theo Bovens said to broadcaster NOS.
Belgium's Presqu'ile de L'llal and Presqu'ile d'Eijsden are being swapped for Dutch land called Presqu'ile Petit-Gravier.
The meandering Meuse river was straightened in 1961, putting the three pieces in the wrong country.
NOS said the situation had led to "isolated enclaves of illegality." Belgian police could only access islands by boat and by permission of the Netherlands.
Although no one lives on the islands, illegal parties by drug dealers and sex tourists occurred, NOS said.
"It was a tough job because there are many parties involved," Bovens said. "Not only the ministries of both countries, but also water states, the Land Registry, the provinces, three municipalities and states. You can imagine what it involves."
The land swap will take place in January 2018 if both nations' parliaments approve the treaty.