Suchowola is one of places, called as centre of Europe. Actually there are a few such centers – in Lithuania, Ukraine, Slovakia... Possibly, every research method to fix centre is different, conception of Europe’s territory is considerable matter as well.
The place was known as centre of Europe even from 18th century, when Polish geographers established it.
This following information I took from a tourist website from poland. What is coming next is information I took from somewhere else. not my text not my personal info:
"...The Augustow Canal takes us directly north from the Biebrza Marshes to the Great Augustow Forest and the Suwalki Lake District. Around 100 km long (80 km. within Polish territory), the Canal constitutes a rare feat of past engineering passing through 14 locks and several beautiful lakes, it was designed and built by Ignacy Pradzynski in the years 1824-1839. Today it is used to float timber and as a waterway for local passenger boats, although by far the most frequent travelers on the Canal are canoeists. The 19th century Pradzynski Manor in Augustow houses a small but interesting museum which chronicles the construction of the Canal and includes an exhibition of landscape paintings from the region..."